diff --git a/.github/workflows/arim_lint.yml b/.github/workflows/arim_lint.yml
new file mode 100644
index 00000000..3a59f122
--- /dev/null
+++ b/.github/workflows/arim_lint.yml
@@ -0,0 +1,27 @@
+name: Run linter
+
+on:
+  push:
+    branches: [ "master" ]
+  pull_request:
+    branches: [ "master" ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+    - name: Set up Python
+      uses: actions/setup-python@v5
+      with:
+        python-version: 3.11
+        architecture: 'x64'
+        cache: 'pip'
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        python -m pip install hatch
+    - name: Run linter
+      run: |
+        hatch run lint:check-gh
diff --git a/.github/workflows/arim_test_lint.yml b/.github/workflows/arim_test.yml
similarity index 83%
rename from .github/workflows/arim_test_lint.yml
rename to .github/workflows/arim_test.yml
index bf90ec73..5c141d19 100644
--- a/.github/workflows/arim_test_lint.yml
+++ b/.github/workflows/arim_test.yml
@@ -1,7 +1,7 @@
 # This workflow will install Python dependencies, run tests and lint with a variety of Python versions
 # For more information see: https://docs.github.com/en/actions/automating-builds-and-tests/building-and-testing-python
 
-name: Python package
+name: Run unit tests
 
 on:
   push:
@@ -12,18 +12,20 @@ on:
 jobs:
   build:
     strategy:
-      fail-fast: false
+      fail-fast: true
       matrix:
         python-version: ["3.8", "3.9", "3.10", "3.11"]
         os: [ubuntu-latest, windows-latest]
     runs-on: ${{ matrix.os }}
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v3
+      uses: actions/setup-python@v5
       with:
         python-version: ${{ matrix.python-version }}
+        architecture: 'x64'
+        cache: 'pip'
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 66b16e7f..3150d826 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -11,16 +11,22 @@ There are many way you can contribute to arim, including:
 
 ## Developer installation
 
-A developer installation requires extra packages for testing, the documentation and code quality.
-The recommended method is to use an [editable installation](https://pip.pypa.io/en/stable/reference/pip_install/), as follows:
+A developer installation requires extra packages for testing, running the code formatter and linter, and building the documentation.
+
+The recommended instructions are as follows.
+
+[Install hatch.](https://hatch.pypa.io/latest/install/)
+
+Clone arim repository locally.
+
+Create a new virtual environment and install the dependencies:
 
-1) Duplicate code from git repository
-2) In the root directory which contains ``setup.py``, type in a console:
 ```
-pip install -e .[dev]
+cd arim
+hatch env create
 ```
 
-The ``[dev]`` flags installs recommended packages for developement, as defined in ``extras_require`` in the file ``setup.py``.
+To activate the virtual environment, use `hatch shell`. Refer to [Hatch documentation](https://hatch.pypa.io/latest/intro/) for further details.
 
 
 ## Code quality guidelines
@@ -32,13 +38,18 @@ Meaningful variable and function names, with no or little abbreviation, are in p
 
 arim code follows the general guidelines defined in [Python PEP-8](https://www.python.org/dev/peps/pep-0008/), with the amendments defined in the following sections.
 
-### Code formatting
+### Code formatting and linting
+
+arim uses [black](https://black.readthedocs.io/en/stable/) code formatter and [ruff](https://docs.astral.sh/ruff/) linter.
 
-Python code must be formatted using [black](https://black.readthedocs.io/en/stable/).
-To format a Python file named ``myfile.py``, type in a terminal:
+Format and lint:
 ```
-black myfile.py
+hatch run lint:fmt
 ```
+To only check, without changing the code, use `hatch run lint:check`.
+
+The linter configuration is defined in `pyproject.toml`.
+
 
 ### Docstring
 
@@ -86,10 +97,11 @@ Unit tests ensure that a given function returns intended results at the time of
 Unit testing in arim is powered by [pytest](https://docs.pytest.org).
 The tests are defined in directory ``tests``. Consider adding new tests!
 
-To run the tests, type in a terminal in the root directory which contains ``tests`` and ``arim``:
-
-    pytest
+To run the unit tests, use the following command:
 
+```
+hatch run test
+```
 All tests must pass.
 
 ## Releasing
@@ -103,7 +115,7 @@ To create a release:
 5. Create a wheel package with 
 
 ```
-python setup.py bdist_wheel
+hatch build
 ```
 
 The result is a `.whl` file in the directory ``dist``, for example ``arim-0.8-py3-none-any.whl``.
diff --git a/pyproject.toml b/pyproject.toml
index c98bf950..d3b868a8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -78,25 +78,28 @@ python = ["3.8", "3.9", "3.10", "3.11"]
 [tool.hatch.envs.lint]
 detached = true
 dependencies = [
-  "black>=23.1.0",
-  "mypy>=1.0.0",
-  "ruff>=0.0.243",
+  "black~=23.0",
+  "mypy==1.10.0",
+  "ruff==0.4.7",
 ]
 [tool.hatch.envs.lint.scripts]
-typing = "mypy --install-types --non-interactive {args:src/arim tests}"
-style = [
-  "ruff {args:.}",
+# typing = "mypy --install-types --non-interactive {args:src/arim tests}"
+check = [
+  "ruff check {args:.}",
+  "black --check --diff {args:.}",
+]
+check-gh = [
+  "ruff check --output-format=github {args:.}",
   "black --check --diff {args:.}",
 ]
 fmt = [
   "black {args:.}",
-  "ruff --fix {args:.}",
-  "style",
-]
-all = [
-  "style",
-  "typing",
+  "ruff check --fix {args:.}",
 ]
+# all = [
+#   "check",
+#   "typing",
+# ]
 
 [tool.black]
 target-version = ["py38"]
@@ -105,7 +108,7 @@ line-length = 88
 [tool.ruff]
 target-version = "py38"
 line-length = 88
-select = [
+lint.select = [
   "E",
   "F",
   "NPY",
@@ -113,23 +116,23 @@ select = [
   "UP",
   "W",
 ]
-ignore = [
+lint.ignore = [
   "E731", # lambda are fine
   "E501", # line too long (in practice: only in comment or docstring)
   "NPY002", # legacy np.random API
+  "NPY201", # Temporary: np.complex_ will be removed in numpy 2.0
+  "UP032", # Use f-string instead of `format` call
+  "UP031", # Use format specifiers instead of percent format
 ]
-unfixable = [
+lint.unfixable = [
   # Don't touch unused imports, because we may be reexporting the API in __init__.py
   "F401",
 ]
 
-[tool.ruff.isort]
+[tool.ruff.lint.isort]
 known-first-party = ["arim"]
 
-[tool.ruff.flake8-tidy-imports]
-ban-relative-imports = "all"
-
-[tool.ruff.per-file-ignores]
+[tool.ruff.lint.per-file-ignores]
 # Tests can use magic values, assertions, and relative imports
 "tests/**/*" = ["PLR2004", "S101", "TID252"]