AWS Services to Solutions :

Migration Strategies :

Rehost : Lift and Shift

Recreate the On premises Network only hosted in AWS:
- servers are migrated to EC2 instances
- network configuration are migrated to VPC, subnet, groups, internet and VPN gateways.
- customer benefits from the pay as you go pricing, he can also elevate it's capacity when needed.
- the migration can be automated via AWS VM Import/Export.
- Once hosted on the cloud, it is easier to optimize and reachitecture
Replattform : Lift tinker and shift

Same as Rehost but making cloud optimization. example :
- moving the database to a managed one like (RDS).
- apply elasticity to instances.
- it can use best practices.
Refactor : Modernize

Apply AWS Cloud to modernize the architecture. For example :
- Apply Amazone Aurora instead of RDS.
- Change Monolitic app to microservices to be able to use container and AWS lambda.
Retire :
- shutting non usefull app.
- reduction of cost/management/security.
Retain : Revisit Only migrate what make sense.
Repurchase : hosting SaaS for zero maintenance.

Cloud Architecture Best practices :

Design for failure an nothing fails :

multiple instances
multiple AZ
seperate a server to multiple servers with single functionalities

Built Security in every layer :