diff --git a/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/controllers/account/package-info.java b/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/controllers/account/package-info.java
new file mode 100644
index 00000000..0fab94e5
--- /dev/null
+++ b/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/controllers/account/package-info.java
@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2023 Stéphane Bégaudeau.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+ * associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
+ * LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+@ApplicationModule(
+        allowedDependencies = { "account" }
+)
+package com.svalyn.studio.application.controllers.account;
+
+import org.springframework.modulith.ApplicationModule;
\ No newline at end of file
diff --git a/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/controllers/viewer/ViewerController.java b/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/controllers/viewer/ViewerController.java
index 37330893..ac5a58c5 100644
--- a/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/controllers/viewer/ViewerController.java
+++ b/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/controllers/viewer/ViewerController.java
@@ -19,7 +19,7 @@
 package com.svalyn.studio.application.controllers.viewer;
 
 import com.svalyn.studio.application.services.account.api.IAccountService;
-import com.svalyn.studio.domain.authentication.IUser;
+import com.svalyn.studio.domain.account.IUser;
 import org.springframework.graphql.data.method.annotation.QueryMapping;
 import org.springframework.security.core.annotation.AuthenticationPrincipal;
 import org.springframework.stereotype.Controller;
diff --git a/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/listeners/notification/AccountModifiedEventListener.java b/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/listeners/notification/AccountModifiedEventListener.java
index e642a6b2..36aa7dd2 100644
--- a/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/listeners/notification/AccountModifiedEventListener.java
+++ b/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/listeners/notification/AccountModifiedEventListener.java
@@ -20,7 +20,7 @@
 package com.svalyn.studio.application.listeners.notification;
 
 import com.svalyn.studio.domain.account.events.AccountModifiedEvent;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.notification.Notification;
 import com.svalyn.studio.domain.notification.repositories.INotificationRepository;
 import org.springframework.stereotype.Service;
diff --git a/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/listeners/notification/OrganizationCreatedEventListener.java b/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/listeners/notification/OrganizationCreatedEventListener.java
index faa37a59..e498a515 100644
--- a/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/listeners/notification/OrganizationCreatedEventListener.java
+++ b/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/listeners/notification/OrganizationCreatedEventListener.java
@@ -19,7 +19,7 @@
 
 package com.svalyn.studio.application.listeners.notification;
 
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.notification.Notification;
 import com.svalyn.studio.domain.notification.repositories.INotificationRepository;
 import com.svalyn.studio.domain.organization.events.OrganizationCreatedEvent;
diff --git a/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/listeners/notification/ProjectCreatedEventListener.java b/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/listeners/notification/ProjectCreatedEventListener.java
index 8c549801..a3a7044e 100644
--- a/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/listeners/notification/ProjectCreatedEventListener.java
+++ b/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/listeners/notification/ProjectCreatedEventListener.java
@@ -19,7 +19,7 @@
 
 package com.svalyn.studio.application.listeners.notification;
 
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.notification.Notification;
 import com.svalyn.studio.domain.notification.repositories.INotificationRepository;
 import com.svalyn.studio.domain.organization.Membership;
diff --git a/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/listeners/notification/ProjectDeletedEventListener.java b/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/listeners/notification/ProjectDeletedEventListener.java
index a3192e8c..0227e2b2 100644
--- a/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/listeners/notification/ProjectDeletedEventListener.java
+++ b/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/listeners/notification/ProjectDeletedEventListener.java
@@ -19,7 +19,7 @@
 
 package com.svalyn.studio.application.listeners.notification;
 
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.notification.Notification;
 import com.svalyn.studio.domain.notification.repositories.INotificationRepository;
 import com.svalyn.studio.domain.organization.Membership;
diff --git a/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/listeners/notification/ProjectModifiedEventListener.java b/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/listeners/notification/ProjectModifiedEventListener.java
index 80c3fe3f..b045eca4 100644
--- a/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/listeners/notification/ProjectModifiedEventListener.java
+++ b/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/listeners/notification/ProjectModifiedEventListener.java
@@ -19,7 +19,7 @@
 
 package com.svalyn.studio.application.listeners.notification;
 
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.notification.Notification;
 import com.svalyn.studio.domain.notification.repositories.INotificationRepository;
 import com.svalyn.studio.domain.organization.Membership;
diff --git a/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/services/account/AuthenticationTokenService.java b/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/services/account/AuthenticationTokenService.java
index dd22c311..643bb304 100644
--- a/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/services/account/AuthenticationTokenService.java
+++ b/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/services/account/AuthenticationTokenService.java
@@ -35,7 +35,7 @@
 import com.svalyn.studio.domain.account.AuthenticationTokenCreated;
 import com.svalyn.studio.domain.account.repositories.IAccountRepository;
 import com.svalyn.studio.domain.account.services.api.IAccountUpdateService;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageImpl;
 import org.springframework.data.domain.PageRequest;
diff --git a/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/services/account/package-info.java b/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/services/account/package-info.java
new file mode 100644
index 00000000..240ce81c
--- /dev/null
+++ b/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/services/account/package-info.java
@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2023 Stéphane Bégaudeau.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+ * associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
+ * LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+@ApplicationModule(
+        allowedDependencies = { "account", "account::api" }
+)
+package com.svalyn.studio.application.services.account;
+
+import org.springframework.modulith.ApplicationModule;
\ No newline at end of file
diff --git a/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/services/notification/NotificationService.java b/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/services/notification/NotificationService.java
index e09b529b..cd1e082a 100644
--- a/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/services/notification/NotificationService.java
+++ b/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/services/notification/NotificationService.java
@@ -30,7 +30,7 @@
 import com.svalyn.studio.domain.Failure;
 import com.svalyn.studio.domain.Success;
 import com.svalyn.studio.domain.account.repositories.IAccountRepository;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.notification.Notification;
 import com.svalyn.studio.domain.notification.NotificationStatus;
 import com.svalyn.studio.domain.notification.repositories.INotificationRepository;
diff --git a/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/services/organization/InvitationService.java b/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/services/organization/InvitationService.java
index f0dc9427..0bd78363 100644
--- a/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/services/organization/InvitationService.java
+++ b/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/services/organization/InvitationService.java
@@ -34,7 +34,7 @@
 import com.svalyn.studio.domain.Failure;
 import com.svalyn.studio.domain.Success;
 import com.svalyn.studio.domain.account.repositories.IAccountRepository;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.message.api.IMessageService;
 import com.svalyn.studio.domain.organization.Invitation;
 import com.svalyn.studio.domain.organization.Organization;
diff --git a/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/services/organization/OrganizationService.java b/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/services/organization/OrganizationService.java
index 8ff5fb53..31491c4d 100644
--- a/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/services/organization/OrganizationService.java
+++ b/backend/svalyn-studio-application/src/main/java/com/svalyn/studio/application/services/organization/OrganizationService.java
@@ -34,7 +34,7 @@
 import com.svalyn.studio.domain.Failure;
 import com.svalyn.studio.domain.Success;
 import com.svalyn.studio.domain.account.repositories.IAccountRepository;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.organization.Organization;
 import com.svalyn.studio.domain.organization.repositories.IOrganizationRepository;
 import com.svalyn.studio.domain.organization.services.api.IOrganizationCreationService;
diff --git a/backend/svalyn-studio-domain/pom.xml b/backend/svalyn-studio-domain/pom.xml
index 3f8275bc..654184b7 100644
--- a/backend/svalyn-studio-domain/pom.xml
+++ b/backend/svalyn-studio-domain/pom.xml
@@ -40,6 +40,25 @@
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     </properties>
 
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>org.springframework.modulith</groupId>
+                <artifactId>spring-modulith-bom</artifactId>
+                <version>1.0.0</version>
+                <scope>import</scope>
+                <type>pom</type>
+            </dependency>
+            <dependency>
+                <groupId>org.jmolecules</groupId>
+                <artifactId>jmolecules-bom</artifactId>
+                <version>2023.1.0</version>
+                <scope>import</scope>
+                <type>pom</type>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
+
     <dependencies>
         <dependency>
             <groupId>org.springframework.boot</groupId>
@@ -78,5 +97,25 @@
             <artifactId>org.eclipse.emf.ecore.xmi</artifactId>
             <version>2.17.0</version>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.modulith</groupId>
+            <artifactId>spring-modulith-core</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.jmolecules</groupId>
+            <artifactId>jmolecules-ddd</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.modulith</groupId>
+            <artifactId>spring-modulith-starter-test</artifactId>
+            <version>1.0.0</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 </project>
\ No newline at end of file
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/Account.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/Account.java
index 0b109f62..129e5b15 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/Account.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/Account.java
@@ -27,7 +27,7 @@
 import com.svalyn.studio.domain.account.events.AuthenticationTokenCreatedEvent;
 import com.svalyn.studio.domain.account.events.AuthenticationTokenModifiedEvent;
 import com.svalyn.studio.domain.account.events.OAuth2MetadataCreatedEvent;
-import com.svalyn.studio.domain.authentication.ProfileProvider;
+import org.jmolecules.ddd.annotation.AggregateRoot;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.annotation.Transient;
 import org.springframework.data.domain.Persistable;
@@ -48,6 +48,7 @@
  *
  * @author sbegaudeau
  */
+@AggregateRoot
 @Table(name = "account")
 public class Account extends AbstractValidatingAggregateRoot<Account> implements Persistable<UUID> {
 
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/authentication/IUser.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/IUser.java
similarity index 93%
rename from backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/authentication/IUser.java
rename to backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/IUser.java
index 2363abb6..a193e9da 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/authentication/IUser.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/IUser.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022 Stéphane Bégaudeau.
+ * Copyright (c) 2022-2023 Stéphane Bégaudeau.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
  * associated documentation files (the "Software"), to deal in the Software without restriction,
@@ -16,7 +16,7 @@
  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
-package com.svalyn.studio.domain.authentication;
+package com.svalyn.studio.domain.account;
 
 import java.util.UUID;
 
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/authentication/ProfileProvider.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/ProfileProvider.java
similarity index 97%
rename from backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/authentication/ProfileProvider.java
rename to backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/ProfileProvider.java
index 111a558d..6bfba8d0 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/authentication/ProfileProvider.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/ProfileProvider.java
@@ -17,7 +17,7 @@
  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
-package com.svalyn.studio.domain.authentication;
+package com.svalyn.studio.domain.account;
 
 import com.svalyn.studio.domain.Profile;
 import org.springframework.security.core.Authentication;
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/authentication/UserIdProvider.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/UserIdProvider.java
similarity index 93%
rename from backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/authentication/UserIdProvider.java
rename to backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/UserIdProvider.java
index f1fecb68..3bc11ee6 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/authentication/UserIdProvider.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/UserIdProvider.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022 Stéphane Bégaudeau.
+ * Copyright (c) 2022-2023 Stéphane Bégaudeau.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
  * associated documentation files (the "Software"), to deal in the Software without restriction,
@@ -16,9 +16,8 @@
  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
-package com.svalyn.studio.domain.authentication;
+package com.svalyn.studio.domain.account;
 
-import com.svalyn.studio.domain.account.Account;
 import org.springframework.data.jdbc.core.mapping.AggregateReference;
 import org.springframework.security.core.Authentication;
 import org.springframework.security.core.context.SecurityContextHolder;
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/package-info.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/package-info.java
new file mode 100644
index 00000000..4b6632af
--- /dev/null
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/package-info.java
@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2023 Stéphane Bégaudeau.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+ * associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
+ * LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+@ApplicationModule(
+        allowedDependencies = { "message::api" }
+)
+package com.svalyn.studio.domain.account;
+
+import org.springframework.modulith.ApplicationModule;
\ No newline at end of file
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/repositories/package-info.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/repositories/package-info.java
new file mode 100644
index 00000000..ac3a3335
--- /dev/null
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/repositories/package-info.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2023 Stéphane Bégaudeau.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+ * associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
+ * LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+@NamedInterface("repositories")
+package com.svalyn.studio.domain.account.repositories;
+
+import org.springframework.modulith.NamedInterface;
\ No newline at end of file
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/services/AccountUpdateService.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/services/AccountUpdateService.java
index 069a9b5e..923ebbed 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/services/AccountUpdateService.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/services/AccountUpdateService.java
@@ -28,7 +28,7 @@
 import com.svalyn.studio.domain.account.repositories.IAccountRepository;
 import com.svalyn.studio.domain.account.services.api.IAccountUpdateService;
 import com.svalyn.studio.domain.account.services.api.IPasswordGenerator;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.message.api.IMessageService;
 import org.springframework.security.crypto.password.PasswordEncoder;
 import org.springframework.stereotype.Service;
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/services/AuthorizationService.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/services/AuthorizationService.java
index 552af7ed..b043cc34 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/services/AuthorizationService.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/services/AuthorizationService.java
@@ -21,7 +21,7 @@
 
 import com.svalyn.studio.domain.account.AccountRole;
 import com.svalyn.studio.domain.account.services.api.IAuthorizationService;
-import com.svalyn.studio.domain.authentication.IUser;
+import com.svalyn.studio.domain.account.IUser;
 import org.springframework.security.core.Authentication;
 import org.springframework.security.core.authority.SimpleGrantedAuthority;
 import org.springframework.security.core.context.SecurityContextHolder;
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/services/api/package-info.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/services/api/package-info.java
new file mode 100644
index 00000000..48578934
--- /dev/null
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/account/services/api/package-info.java
@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2023 Stéphane Bégaudeau.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+ * associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
+ * LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+@NamedInterface("api")
+package com.svalyn.studio.domain.account.services.api;
+
+import org.springframework.modulith.NamedInterface;
\ No newline at end of file
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/activity/ActivityEntry.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/activity/ActivityEntry.java
index 54e2edfc..060fdf02 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/activity/ActivityEntry.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/activity/ActivityEntry.java
@@ -22,8 +22,9 @@
 import com.svalyn.studio.domain.AbstractValidatingAggregateRoot;
 import com.svalyn.studio.domain.account.Account;
 import com.svalyn.studio.domain.activity.events.ActivityEntryCreatedEvent;
-import com.svalyn.studio.domain.authentication.ProfileProvider;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.ProfileProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
+import org.jmolecules.ddd.annotation.AggregateRoot;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.annotation.Transient;
 import org.springframework.data.domain.Persistable;
@@ -39,6 +40,7 @@
  *
  * @author sbegaudeau
  */
+@AggregateRoot
 @Table("activity")
 public class ActivityEntry extends AbstractValidatingAggregateRoot<ActivityEntry> implements Persistable<UUID> {
     @Transient
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/activity/OrganizationActivityEntry.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/activity/OrganizationActivityEntry.java
index 0d83882f..2c16f32c 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/activity/OrganizationActivityEntry.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/activity/OrganizationActivityEntry.java
@@ -21,8 +21,9 @@
 
 import com.svalyn.studio.domain.AbstractValidatingAggregateRoot;
 import com.svalyn.studio.domain.activity.events.OrganizationActivityEntryCreatedEvent;
-import com.svalyn.studio.domain.authentication.ProfileProvider;
+import com.svalyn.studio.domain.account.ProfileProvider;
 import com.svalyn.studio.domain.organization.Organization;
+import org.jmolecules.ddd.annotation.AggregateRoot;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.annotation.Transient;
 import org.springframework.data.domain.Persistable;
@@ -39,6 +40,7 @@
  *
  * @author sbegaudeau
  */
+@AggregateRoot
 @Table("organization_activity")
 public class OrganizationActivityEntry extends AbstractValidatingAggregateRoot<OrganizationActivityEntry> implements Persistable<UUID> {
     @Transient
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/activity/ProjectActivityEntry.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/activity/ProjectActivityEntry.java
index aa47983a..11e0606c 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/activity/ProjectActivityEntry.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/activity/ProjectActivityEntry.java
@@ -21,8 +21,9 @@
 
 import com.svalyn.studio.domain.AbstractValidatingAggregateRoot;
 import com.svalyn.studio.domain.activity.events.ProjectActivityEntryCreatedEvent;
-import com.svalyn.studio.domain.authentication.ProfileProvider;
+import com.svalyn.studio.domain.account.ProfileProvider;
 import com.svalyn.studio.domain.project.Project;
+import org.jmolecules.ddd.annotation.AggregateRoot;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.annotation.Transient;
 import org.springframework.data.domain.Persistable;
@@ -39,6 +40,7 @@
  *
  * @author sbegaudeau
  */
+@AggregateRoot
 @Table("project_activity")
 public class ProjectActivityEntry extends AbstractValidatingAggregateRoot<ProjectActivityEntry> implements Persistable<UUID> {
     @Transient
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/business/Domain.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/business/Domain.java
index 5b020947..1e702884 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/business/Domain.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/business/Domain.java
@@ -21,9 +21,10 @@
 
 import com.svalyn.studio.domain.AbstractValidatingAggregateRoot;
 import com.svalyn.studio.domain.account.Account;
-import com.svalyn.studio.domain.authentication.ProfileProvider;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.ProfileProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.business.events.DomainCreatedEvent;
+import org.jmolecules.ddd.annotation.AggregateRoot;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.annotation.Transient;
 import org.springframework.data.domain.Persistable;
@@ -39,6 +40,7 @@
  *
  * @author sbegaudeau
  */
+@AggregateRoot
 @Table("domain")
 public class Domain extends AbstractValidatingAggregateRoot<Domain> implements Persistable<UUID> {
     @Transient
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/Branch.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/Branch.java
index d62010dd..1d2fd296 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/Branch.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/Branch.java
@@ -21,11 +21,12 @@
 
 import com.svalyn.studio.domain.AbstractValidatingAggregateRoot;
 import com.svalyn.studio.domain.account.Account;
-import com.svalyn.studio.domain.authentication.ProfileProvider;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.ProfileProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.history.events.BranchCreatedEvent;
 import com.svalyn.studio.domain.history.events.BranchModifiedEvent;
 import com.svalyn.studio.domain.project.Project;
+import org.jmolecules.ddd.annotation.AggregateRoot;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.annotation.Transient;
 import org.springframework.data.domain.Persistable;
@@ -42,6 +43,7 @@
  *
  * @author sbegaudeau
  */
+@AggregateRoot
 @Table("branch")
 public class Branch extends AbstractValidatingAggregateRoot<Branch> implements Persistable<UUID> {
     @Transient
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/Change.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/Change.java
index d7ec8303..a1486f68 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/Change.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/Change.java
@@ -21,12 +21,13 @@
 
 import com.svalyn.studio.domain.AbstractValidatingAggregateRoot;
 import com.svalyn.studio.domain.account.Account;
-import com.svalyn.studio.domain.authentication.ProfileProvider;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.ProfileProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.history.events.ChangeCreatedEvent;
 import com.svalyn.studio.domain.history.events.ChangeDeletedEvent;
 import com.svalyn.studio.domain.history.events.ResourcesAddedToChangeEvent;
 import com.svalyn.studio.domain.history.events.ResourcesRemovedFromChangeEvent;
+import org.jmolecules.ddd.annotation.AggregateRoot;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.annotation.Transient;
 import org.springframework.data.domain.Persistable;
@@ -47,6 +48,7 @@
  *
  * @author sbegaudeau
  */
+@AggregateRoot
 @Table("change")
 public class Change extends AbstractValidatingAggregateRoot<Change> implements Persistable<UUID> {
 
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/ChangeProposal.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/ChangeProposal.java
index bb9359d6..68eb4c01 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/ChangeProposal.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/ChangeProposal.java
@@ -21,8 +21,8 @@
 
 import com.svalyn.studio.domain.AbstractValidatingAggregateRoot;
 import com.svalyn.studio.domain.account.Account;
-import com.svalyn.studio.domain.authentication.ProfileProvider;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.ProfileProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.history.events.ChangeProposalCreatedEvent;
 import com.svalyn.studio.domain.history.events.ChangeProposalDeletedEvent;
 import com.svalyn.studio.domain.history.events.ChangeProposalIntegratedEvent;
@@ -30,6 +30,7 @@
 import com.svalyn.studio.domain.history.events.ReviewModifiedEvent;
 import com.svalyn.studio.domain.history.events.ReviewPerformedEvent;
 import com.svalyn.studio.domain.project.Project;
+import org.jmolecules.ddd.annotation.AggregateRoot;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.annotation.Transient;
 import org.springframework.data.domain.Persistable;
@@ -49,6 +50,7 @@
  *
  * @author sbegaudeau
  */
+@AggregateRoot
 @Table("change_proposal")
 public class ChangeProposal extends AbstractValidatingAggregateRoot<ChangeProposal> implements Persistable<UUID> {
     @Transient
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/Review.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/Review.java
index 288c8142..a7867045 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/Review.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/Review.java
@@ -20,7 +20,7 @@
 package com.svalyn.studio.domain.history;
 
 import com.svalyn.studio.domain.account.Account;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.jdbc.core.mapping.AggregateReference;
 import org.springframework.data.relational.core.mapping.Table;
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/package-info.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/package-info.java
new file mode 100644
index 00000000..676e173a
--- /dev/null
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/package-info.java
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2023 Stéphane Bégaudeau.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+ * associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
+ * LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+@ApplicationModule(
+        allowedDependencies = {
+                "account",
+                "organization",
+                "organization::api",
+                "project",
+                "project::repositories",
+                "resource",
+                "resource::repositories",
+                "message::api"
+        }
+)
+package com.svalyn.studio.domain.history;
+
+import org.springframework.modulith.ApplicationModule;
\ No newline at end of file
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/services/ChangeProposalCreationService.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/services/ChangeProposalCreationService.java
index 1aa8bfa4..4a491950 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/services/ChangeProposalCreationService.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/services/ChangeProposalCreationService.java
@@ -22,7 +22,7 @@
 import com.svalyn.studio.domain.Failure;
 import com.svalyn.studio.domain.IResult;
 import com.svalyn.studio.domain.Success;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.history.Change;
 import com.svalyn.studio.domain.history.ChangeProposal;
 import com.svalyn.studio.domain.history.ChangeResource;
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/services/ChangeProposalDeletionService.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/services/ChangeProposalDeletionService.java
index d034c416..510d38d6 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/services/ChangeProposalDeletionService.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/services/ChangeProposalDeletionService.java
@@ -22,7 +22,7 @@
 import com.svalyn.studio.domain.Failure;
 import com.svalyn.studio.domain.IResult;
 import com.svalyn.studio.domain.Success;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.history.ChangeProposal;
 import com.svalyn.studio.domain.history.repositories.IChangeProposalRepository;
 import com.svalyn.studio.domain.history.services.api.IChangeProposalDeletionService;
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/services/ChangeProposalUpdateService.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/services/ChangeProposalUpdateService.java
index 5f1d1065..941c7ced 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/services/ChangeProposalUpdateService.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/history/services/ChangeProposalUpdateService.java
@@ -22,7 +22,7 @@
 import com.svalyn.studio.domain.Failure;
 import com.svalyn.studio.domain.IResult;
 import com.svalyn.studio.domain.Success;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.history.ChangeProposal;
 import com.svalyn.studio.domain.history.ChangeProposalStatus;
 import com.svalyn.studio.domain.history.ChangeResource;
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/message/api/package-info.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/message/api/package-info.java
new file mode 100644
index 00000000..285f5e58
--- /dev/null
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/message/api/package-info.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2023 Stéphane Bégaudeau.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+ * associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
+ * LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+@NamedInterface("api")
+package com.svalyn.studio.domain.message.api;
+
+import org.springframework.modulith.NamedInterface;
\ No newline at end of file
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/message/package-info.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/message/package-info.java
new file mode 100644
index 00000000..04cd02b8
--- /dev/null
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/message/package-info.java
@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2023 Stéphane Bégaudeau.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+ * associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
+ * LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+@ApplicationModule(
+        allowedDependencies = { }
+)
+package com.svalyn.studio.domain.message;
+
+import org.springframework.modulith.ApplicationModule;
\ No newline at end of file
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/notification/Notification.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/notification/Notification.java
index 693f97b7..0de3bfac 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/notification/Notification.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/notification/Notification.java
@@ -21,12 +21,13 @@
 
 import com.svalyn.studio.domain.AbstractValidatingAggregateRoot;
 import com.svalyn.studio.domain.account.Account;
-import com.svalyn.studio.domain.authentication.ProfileProvider;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.ProfileProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.notification.events.NotificationCreatedEvent;
 import com.svalyn.studio.domain.notification.events.NotificationMarkedAsDoneEvent;
 import com.svalyn.studio.domain.notification.events.NotificationMarkedAsReadEvent;
 import com.svalyn.studio.domain.notification.events.NotificationMarkedAsUnreadEvent;
+import org.jmolecules.ddd.annotation.AggregateRoot;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.annotation.Transient;
 import org.springframework.data.domain.Persistable;
@@ -42,6 +43,7 @@
  *
  * @author sbegaudeau
  */
+@AggregateRoot
 @Table("notification")
 public class Notification extends AbstractValidatingAggregateRoot<Notification> implements Persistable<UUID> {
 
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/notification/package-info.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/notification/package-info.java
new file mode 100644
index 00000000..80678b29
--- /dev/null
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/notification/package-info.java
@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2023 Stéphane Bégaudeau.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+ * associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
+ * LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+@ApplicationModule(
+        allowedDependencies = { "account" }
+)
+package com.svalyn.studio.domain.notification;
+
+import org.springframework.modulith.ApplicationModule;
\ No newline at end of file
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/notification/services/NotificationUpdateService.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/notification/services/NotificationUpdateService.java
index 0716400d..13ac2469 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/notification/services/NotificationUpdateService.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/notification/services/NotificationUpdateService.java
@@ -21,7 +21,7 @@
 
 import com.svalyn.studio.domain.IResult;
 import com.svalyn.studio.domain.Success;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.notification.NotificationStatus;
 import com.svalyn.studio.domain.notification.repositories.INotificationRepository;
 import com.svalyn.studio.domain.notification.services.api.INotificationUpdateService;
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/Invitation.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/Invitation.java
index 8a303898..127610a1 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/Invitation.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/Invitation.java
@@ -19,7 +19,7 @@
 package com.svalyn.studio.domain.organization;
 
 import com.svalyn.studio.domain.account.Account;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.jdbc.core.mapping.AggregateReference;
 import org.springframework.data.relational.core.mapping.Table;
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/Membership.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/Membership.java
index 259df124..39c414eb 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/Membership.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/Membership.java
@@ -19,7 +19,7 @@
 package com.svalyn.studio.domain.organization;
 
 import com.svalyn.studio.domain.account.Account;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.jdbc.core.mapping.AggregateReference;
 import org.springframework.data.relational.core.mapping.Table;
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/Organization.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/Organization.java
index abeae5ed..cdf77b80 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/Organization.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/Organization.java
@@ -20,8 +20,8 @@
 
 import com.svalyn.studio.domain.AbstractValidatingAggregateRoot;
 import com.svalyn.studio.domain.account.Account;
-import com.svalyn.studio.domain.authentication.ProfileProvider;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.ProfileProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.organization.events.InvitationAcceptedEvent;
 import com.svalyn.studio.domain.organization.events.InvitationDeclinedEvent;
 import com.svalyn.studio.domain.organization.events.InvitationRevokedEvent;
@@ -31,6 +31,7 @@
 import com.svalyn.studio.domain.organization.events.OrganizationCreatedEvent;
 import com.svalyn.studio.domain.organization.events.OrganizationDeletedEvent;
 import com.svalyn.studio.domain.organization.events.OrganizationModifiedEvent;
+import org.jmolecules.ddd.annotation.AggregateRoot;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.annotation.Transient;
 import org.springframework.data.domain.Persistable;
@@ -54,6 +55,7 @@
  *
  * @author sbegaudeau
  */
+@AggregateRoot
 @Table("organization")
 public class Organization extends AbstractValidatingAggregateRoot<Organization> implements Persistable<UUID> {
 
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/package-info.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/package-info.java
new file mode 100644
index 00000000..a94a3911
--- /dev/null
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/package-info.java
@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2023 Stéphane Bégaudeau.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+ * associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
+ * LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+@ApplicationModule(
+        allowedDependencies = { "account", "account::repositories", "message::api" }
+)
+package com.svalyn.studio.domain.organization;
+
+import org.springframework.modulith.ApplicationModule;
\ No newline at end of file
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/repositories/package-info.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/repositories/package-info.java
new file mode 100644
index 00000000..ae10170d
--- /dev/null
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/repositories/package-info.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2023 Stéphane Bégaudeau.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+ * associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
+ * LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+@NamedInterface("repositories")
+package com.svalyn.studio.domain.organization.repositories;
+
+import org.springframework.modulith.NamedInterface;
\ No newline at end of file
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/services/OrganizationCreationService.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/services/OrganizationCreationService.java
index 4e4adeb4..dff39cee 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/services/OrganizationCreationService.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/services/OrganizationCreationService.java
@@ -22,7 +22,7 @@
 import com.svalyn.studio.domain.Failure;
 import com.svalyn.studio.domain.IResult;
 import com.svalyn.studio.domain.Success;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.message.api.IMessageService;
 import com.svalyn.studio.domain.organization.Organization;
 import com.svalyn.studio.domain.organization.repositories.IOrganizationRepository;
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/services/OrganizationDeletionService.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/services/OrganizationDeletionService.java
index 0633408b..b348e404 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/services/OrganizationDeletionService.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/services/OrganizationDeletionService.java
@@ -22,7 +22,7 @@
 import com.svalyn.studio.domain.Failure;
 import com.svalyn.studio.domain.IResult;
 import com.svalyn.studio.domain.Success;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.message.api.IMessageService;
 import com.svalyn.studio.domain.organization.MembershipRole;
 import com.svalyn.studio.domain.organization.repositories.IOrganizationRepository;
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/services/OrganizationUpdateService.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/services/OrganizationUpdateService.java
index ec363a81..107dabd2 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/services/OrganizationUpdateService.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/services/OrganizationUpdateService.java
@@ -22,7 +22,7 @@
 import com.svalyn.studio.domain.Failure;
 import com.svalyn.studio.domain.IResult;
 import com.svalyn.studio.domain.Success;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.message.api.IMessageService;
 import com.svalyn.studio.domain.organization.MembershipRole;
 import com.svalyn.studio.domain.organization.repositories.IOrganizationRepository;
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/services/api/package-info.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/services/api/package-info.java
new file mode 100644
index 00000000..4543506f
--- /dev/null
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/organization/services/api/package-info.java
@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2023 Stéphane Bégaudeau.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+ * associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
+ * LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+@NamedInterface("api")
+package com.svalyn.studio.domain.organization.services.api;
+
+import org.springframework.modulith.NamedInterface;
\ No newline at end of file
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/project/Project.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/project/Project.java
index e3cf832c..10d27b16 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/project/Project.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/project/Project.java
@@ -21,12 +21,13 @@
 
 import com.svalyn.studio.domain.AbstractValidatingAggregateRoot;
 import com.svalyn.studio.domain.account.Account;
-import com.svalyn.studio.domain.authentication.ProfileProvider;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.ProfileProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.organization.Organization;
 import com.svalyn.studio.domain.project.events.ProjectCreatedEvent;
 import com.svalyn.studio.domain.project.events.ProjectDeletedEvent;
 import com.svalyn.studio.domain.project.events.ProjectModifiedEvent;
+import org.jmolecules.ddd.annotation.AggregateRoot;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.annotation.Transient;
 import org.springframework.data.domain.Persistable;
@@ -43,6 +44,7 @@
  *
  * @author sbegaudeau
  */
+@AggregateRoot
 @Table("project")
 public class Project extends AbstractValidatingAggregateRoot<Project> implements Persistable<UUID> {
 
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/project/package-info.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/project/package-info.java
new file mode 100644
index 00000000..b10ddad5
--- /dev/null
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/project/package-info.java
@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2023 Stéphane Bégaudeau.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+ * associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
+ * LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+@ApplicationModule(
+        allowedDependencies = {
+                "account",
+                "organization",
+                "organization::api",
+                "organization::repositories",
+                "message::api"
+        }
+)
+package com.svalyn.studio.domain.project;
+
+import org.springframework.modulith.ApplicationModule;
\ No newline at end of file
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/project/repositories/package-info.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/project/repositories/package-info.java
new file mode 100644
index 00000000..560b39b9
--- /dev/null
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/project/repositories/package-info.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2023 Stéphane Bégaudeau.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+ * associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
+ * LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+@NamedInterface("repositories")
+package com.svalyn.studio.domain.project.repositories;
+
+import org.springframework.modulith.NamedInterface;
\ No newline at end of file
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/project/services/ProjectCreationService.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/project/services/ProjectCreationService.java
index 09f3101f..e25e6e9c 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/project/services/ProjectCreationService.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/project/services/ProjectCreationService.java
@@ -22,7 +22,7 @@
 import com.svalyn.studio.domain.Failure;
 import com.svalyn.studio.domain.IResult;
 import com.svalyn.studio.domain.Success;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.message.api.IMessageService;
 import com.svalyn.studio.domain.organization.MembershipRole;
 import com.svalyn.studio.domain.organization.repositories.IOrganizationRepository;
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/project/services/ProjectDeletionService.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/project/services/ProjectDeletionService.java
index fc956762..98ff5882 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/project/services/ProjectDeletionService.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/project/services/ProjectDeletionService.java
@@ -22,7 +22,7 @@
 import com.svalyn.studio.domain.Failure;
 import com.svalyn.studio.domain.IResult;
 import com.svalyn.studio.domain.Success;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.message.api.IMessageService;
 import com.svalyn.studio.domain.organization.MembershipRole;
 import com.svalyn.studio.domain.organization.repositories.IOrganizationRepository;
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/project/services/ProjectUpdateService.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/project/services/ProjectUpdateService.java
index fbeb1ec2..5934b39e 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/project/services/ProjectUpdateService.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/project/services/ProjectUpdateService.java
@@ -22,7 +22,7 @@
 import com.svalyn.studio.domain.Failure;
 import com.svalyn.studio.domain.IResult;
 import com.svalyn.studio.domain.Success;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.message.api.IMessageService;
 import com.svalyn.studio.domain.organization.MembershipRole;
 import com.svalyn.studio.domain.organization.repositories.IOrganizationRepository;
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/resource/Resource.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/resource/Resource.java
index 8b8c115c..602eb0b9 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/resource/Resource.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/resource/Resource.java
@@ -21,10 +21,11 @@
 
 import com.svalyn.studio.domain.AbstractValidatingAggregateRoot;
 import com.svalyn.studio.domain.account.Account;
-import com.svalyn.studio.domain.authentication.ProfileProvider;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.ProfileProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.resource.events.ResourceCreatedEvent;
 import com.svalyn.studio.domain.resource.events.ResourceDeletedEvent;
+import org.jmolecules.ddd.annotation.AggregateRoot;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.annotation.Transient;
 import org.springframework.data.domain.Persistable;
@@ -40,6 +41,7 @@
  *
  * @author sbegaudeau
  */
+@AggregateRoot
 @Table("resource")
 public class Resource extends AbstractValidatingAggregateRoot<Resource> implements Persistable<UUID> {
 
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/resource/package-info.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/resource/package-info.java
new file mode 100644
index 00000000..8298e482
--- /dev/null
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/resource/package-info.java
@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2023 Stéphane Bégaudeau.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+ * associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
+ * LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+@ApplicationModule(
+        allowedDependencies = { "account", "message::api" }
+)
+package com.svalyn.studio.domain.resource;
+
+import org.springframework.modulith.ApplicationModule;
\ No newline at end of file
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/resource/repositories/package-info.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/resource/repositories/package-info.java
new file mode 100644
index 00000000..7f206a80
--- /dev/null
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/resource/repositories/package-info.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2023 Stéphane Bégaudeau.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+ * associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
+ * LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+@NamedInterface("repositories")
+package com.svalyn.studio.domain.resource.repositories;
+
+import org.springframework.modulith.NamedInterface;
\ No newline at end of file
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/tag/OrganizationTag.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/tag/OrganizationTag.java
index 24a5baeb..8c46ef18 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/tag/OrganizationTag.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/tag/OrganizationTag.java
@@ -21,10 +21,11 @@
 
 import com.svalyn.studio.domain.AbstractValidatingAggregateRoot;
 import com.svalyn.studio.domain.account.Account;
-import com.svalyn.studio.domain.authentication.ProfileProvider;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.ProfileProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.organization.Organization;
 import com.svalyn.studio.domain.tag.events.TagAddedToOrganizationEvent;
+import org.jmolecules.ddd.annotation.AggregateRoot;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.annotation.Transient;
 import org.springframework.data.domain.Persistable;
@@ -41,6 +42,7 @@
  *
  * @author sbegaudeau
  */
+@AggregateRoot
 @Table(name = "organization_tag")
 public class OrganizationTag extends AbstractValidatingAggregateRoot<OrganizationTag> implements Persistable<UUID> {
 
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/tag/ProjectTag.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/tag/ProjectTag.java
index da5d4c40..cd6e7364 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/tag/ProjectTag.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/tag/ProjectTag.java
@@ -21,10 +21,11 @@
 
 import com.svalyn.studio.domain.AbstractValidatingAggregateRoot;
 import com.svalyn.studio.domain.account.Account;
-import com.svalyn.studio.domain.authentication.ProfileProvider;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.ProfileProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.project.Project;
 import com.svalyn.studio.domain.tag.events.TagAddedToProjectEvent;
+import org.jmolecules.ddd.annotation.AggregateRoot;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.annotation.Transient;
 import org.springframework.data.domain.Persistable;
@@ -41,6 +42,7 @@
  *
  * @author sbegaudeau
  */
+@AggregateRoot
 @Table(name = "project_tag")
 public class ProjectTag extends AbstractValidatingAggregateRoot<ProjectTag> implements Persistable<UUID> {
     @Transient
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/tag/Tag.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/tag/Tag.java
index 2ffed4ac..3f5d022a 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/tag/Tag.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/tag/Tag.java
@@ -21,9 +21,10 @@
 
 import com.svalyn.studio.domain.AbstractValidatingAggregateRoot;
 import com.svalyn.studio.domain.account.Account;
-import com.svalyn.studio.domain.authentication.ProfileProvider;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.ProfileProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.tag.events.TagCreatedEvent;
+import org.jmolecules.ddd.annotation.AggregateRoot;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.annotation.Transient;
 import org.springframework.data.domain.Persistable;
@@ -39,6 +40,7 @@
  *
  * @author sbegaudeau
  */
+@AggregateRoot
 @Table("tag")
 public class Tag extends AbstractValidatingAggregateRoot<Tag> implements Persistable<UUID> {
     @Transient
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/tag/package-info.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/tag/package-info.java
new file mode 100644
index 00000000..ef56d196
--- /dev/null
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/tag/package-info.java
@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2023 Stéphane Bégaudeau.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+ * associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
+ * LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+@ApplicationModule(
+        allowedDependencies = {
+                "account",
+                "organization",
+                "organization::api",
+                "organization::repositories",
+                "project",
+                "project::repositories",
+                "message::api"
+        }
+)
+package com.svalyn.studio.domain.tag;
+
+import org.springframework.modulith.ApplicationModule;
\ No newline at end of file
diff --git a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/tag/services/TagCreationService.java b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/tag/services/TagCreationService.java
index c30b2697..d1beaa6c 100644
--- a/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/tag/services/TagCreationService.java
+++ b/backend/svalyn-studio-domain/src/main/java/com/svalyn/studio/domain/tag/services/TagCreationService.java
@@ -22,7 +22,7 @@
 import com.svalyn.studio.domain.Failure;
 import com.svalyn.studio.domain.IResult;
 import com.svalyn.studio.domain.Success;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.message.api.IMessageService;
 import com.svalyn.studio.domain.organization.MembershipRole;
 import com.svalyn.studio.domain.organization.repositories.IOrganizationRepository;
diff --git a/backend/svalyn-studio-domain/src/test/java/com/svalyn/studio/domain/ModularityTests.java b/backend/svalyn-studio-domain/src/test/java/com/svalyn/studio/domain/ModularityTests.java
new file mode 100644
index 00000000..e6abad2e
--- /dev/null
+++ b/backend/svalyn-studio-domain/src/test/java/com/svalyn/studio/domain/ModularityTests.java
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2023 Stéphane Bégaudeau.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+ * associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
+ * LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+package com.svalyn.studio.domain;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.modulith.core.ApplicationModules;
+import org.springframework.modulith.docs.Documenter;
+
+/**
+ * Ensure the respect of the modularity rules of the account aggregate.
+ *
+ * @author sbegaudeau
+ */
+public class ModularityTests {
+
+    private final ApplicationModules domainModules = ApplicationModules.of("com.svalyn.studio.domain");
+
+    @Test
+    public void verifyModules() {
+        this.domainModules.verify();
+
+        new Documenter(this.domainModules).writeDocumentation()
+                .writeModuleCanvases()
+                .writeIndividualModulesAsPlantUml()
+                .writeModulesAsPlantUml();
+    }
+}
diff --git a/backend/svalyn-studio-infrastructure/src/main/java/com/svalyn/studio/infrastructure/security/SvalynOAuth2User.java b/backend/svalyn-studio-infrastructure/src/main/java/com/svalyn/studio/infrastructure/security/SvalynOAuth2User.java
index 084ade75..83180545 100644
--- a/backend/svalyn-studio-infrastructure/src/main/java/com/svalyn/studio/infrastructure/security/SvalynOAuth2User.java
+++ b/backend/svalyn-studio-infrastructure/src/main/java/com/svalyn/studio/infrastructure/security/SvalynOAuth2User.java
@@ -19,7 +19,7 @@
 package com.svalyn.studio.infrastructure.security;
 
 import com.svalyn.studio.domain.account.Account;
-import com.svalyn.studio.domain.authentication.IUser;
+import com.svalyn.studio.domain.account.IUser;
 import org.springframework.security.core.GrantedAuthority;
 import org.springframework.security.core.authority.SimpleGrantedAuthority;
 import org.springframework.security.oauth2.core.OAuth2AccessToken;
diff --git a/backend/svalyn-studio-infrastructure/src/main/java/com/svalyn/studio/infrastructure/security/SvalynSystemUser.java b/backend/svalyn-studio-infrastructure/src/main/java/com/svalyn/studio/infrastructure/security/SvalynSystemUser.java
index 8347f840..6105b523 100644
--- a/backend/svalyn-studio-infrastructure/src/main/java/com/svalyn/studio/infrastructure/security/SvalynSystemUser.java
+++ b/backend/svalyn-studio-infrastructure/src/main/java/com/svalyn/studio/infrastructure/security/SvalynSystemUser.java
@@ -19,7 +19,7 @@
 
 package com.svalyn.studio.infrastructure.security;
 
-import com.svalyn.studio.domain.authentication.IUser;
+import com.svalyn.studio.domain.account.IUser;
 
 import java.io.Serializable;
 import java.util.Objects;
diff --git a/backend/svalyn-studio-infrastructure/src/main/java/com/svalyn/studio/infrastructure/security/SvalynUserDetails.java b/backend/svalyn-studio-infrastructure/src/main/java/com/svalyn/studio/infrastructure/security/SvalynUserDetails.java
index 15f1be77..1f5e6b1a 100644
--- a/backend/svalyn-studio-infrastructure/src/main/java/com/svalyn/studio/infrastructure/security/SvalynUserDetails.java
+++ b/backend/svalyn-studio-infrastructure/src/main/java/com/svalyn/studio/infrastructure/security/SvalynUserDetails.java
@@ -19,7 +19,7 @@
 
 package com.svalyn.studio.infrastructure.security;
 
-import com.svalyn.studio.domain.authentication.IUser;
+import com.svalyn.studio.domain.account.IUser;
 import org.springframework.security.core.GrantedAuthority;
 import org.springframework.security.core.userdetails.User;
 
diff --git a/backend/svalyn-studio/pom.xml b/backend/svalyn-studio/pom.xml
index 6d0d1b0f..8f6ab039 100644
--- a/backend/svalyn-studio/pom.xml
+++ b/backend/svalyn-studio/pom.xml
@@ -95,6 +95,12 @@
             <version>1.0.0</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.modulith</groupId>
+            <artifactId>spring-modulith-starter-test</artifactId>
+            <version>1.0.0</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>
diff --git a/backend/svalyn-studio/src/main/java/com/svalyn/studio/package-info.java b/backend/svalyn-studio/src/main/java/com/svalyn/studio/package-info.java
new file mode 100644
index 00000000..89587d8b
--- /dev/null
+++ b/backend/svalyn-studio/src/main/java/com/svalyn/studio/package-info.java
@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2023 Stéphane Bégaudeau.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+ * associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
+ * LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+@ApplicationModule(
+        allowedDependencies = { }
+)
+package com.svalyn.studio;
+
+import org.springframework.modulith.ApplicationModule;
\ No newline at end of file
diff --git a/backend/svalyn-studio/src/test/java/com/svalyn/studio/ModularityTests.java b/backend/svalyn-studio/src/test/java/com/svalyn/studio/ModularityTests.java
new file mode 100644
index 00000000..baf8d42b
--- /dev/null
+++ b/backend/svalyn-studio/src/test/java/com/svalyn/studio/ModularityTests.java
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2023 Stéphane Bégaudeau.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+ * associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
+ * LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+package com.svalyn.studio;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.modulith.core.ApplicationModules;
+import org.springframework.modulith.docs.Documenter;
+
+/**
+ * Tests of the organization of the application modules.
+ *
+ * @author sbegaudeau
+ */
+public class ModularityTests {
+
+    private final ApplicationModules modules = ApplicationModules.of(SvalynStudio.class);
+
+    @Test
+    public void verifyModules() {
+        this.modules.verify();
+    }
+
+    @Test
+    public void generateDocumentation() {
+        new Documenter(this.modules).writeDocumentation().writeIndividualModulesAsPlantUml();
+    }
+}
diff --git a/backend/svalyn-studio/src/test/java/com/svalyn/studio/WithMockPrincipalSecurityContextFactory.java b/backend/svalyn-studio/src/test/java/com/svalyn/studio/WithMockPrincipalSecurityContextFactory.java
index 32e458ee..36b54dd3 100644
--- a/backend/svalyn-studio/src/test/java/com/svalyn/studio/WithMockPrincipalSecurityContextFactory.java
+++ b/backend/svalyn-studio/src/test/java/com/svalyn/studio/WithMockPrincipalSecurityContextFactory.java
@@ -19,7 +19,7 @@
 package com.svalyn.studio;
 
 import com.svalyn.studio.domain.account.repositories.IAccountRepository;
-import com.svalyn.studio.domain.authentication.IUser;
+import com.svalyn.studio.domain.account.IUser;
 import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
 import org.springframework.security.core.context.SecurityContext;
 import org.springframework.security.core.context.SecurityContextHolder;
diff --git a/backend/svalyn-studio/src/test/java/com/svalyn/studio/domain/notification/OrganizationCreatedEventListenerIntegrationTests.java b/backend/svalyn-studio/src/test/java/com/svalyn/studio/domain/notification/OrganizationCreatedEventListenerIntegrationTests.java
index 0e959a4f..292ec7b8 100644
--- a/backend/svalyn-studio/src/test/java/com/svalyn/studio/domain/notification/OrganizationCreatedEventListenerIntegrationTests.java
+++ b/backend/svalyn-studio/src/test/java/com/svalyn/studio/domain/notification/OrganizationCreatedEventListenerIntegrationTests.java
@@ -23,7 +23,7 @@
 import com.svalyn.studio.DomainEvents;
 import com.svalyn.studio.WithMockPrincipal;
 import com.svalyn.studio.domain.Success;
-import com.svalyn.studio.domain.authentication.UserIdProvider;
+import com.svalyn.studio.domain.account.UserIdProvider;
 import com.svalyn.studio.domain.notification.events.NotificationCreatedEvent;
 import com.svalyn.studio.domain.notification.repositories.INotificationRepository;
 import com.svalyn.studio.domain.organization.events.OrganizationCreatedEvent;