clean-architecture-modular-design

name	clean-architecture-modular-design
description	Use this skill when structuring the project, defining layers, or enforcing architectural boundaries.

When applying Clean Architecture:

1. Enforce strict layers:

   • domain
   • application
   • infrastructure
   • api

2. Dependency rules:

   • Domain depends on nothing
   • Application depends on domain
   • Infrastructure depends on application
   • API depends on application

3. Rules:

   • No Spring annotations in domain
   • No JPA entities leaking into API
   • Use interfaces (ports) at boundaries

4. Business logic:

   • Lives in use cases
   • Not in controllers
   • Not in repositories

Violations must be considered architectural bugs. Always write tests to verify layer boundaries are respected.