Programming Tutorials

  The Blocker: The "Transactional" Annotation Trap You have meticulously designed your Hexagonal Architecture (Ports & Adapters). You have a pristine Domain layer and a segregated Application (Use Case) layer. You have stripped away all frameworks from your core. Then, you write a Use Case that requires atomicity: Deduct inventory. Charge the credit card. Save the order. If any step fails, all must fail. The instinct is to reach for a framework-specific annotation (like Spring’s  @Transactional  or NestJS interceptors) and slap it on the Use Case method. Stop. The moment you import  org.springframework.transaction.annotation.Transactional  (or similar) into your Use Case layer, you have violated the  Dependency Rule . Your inner circle now depends on a framework mechanism living in the outer circle. You are no longer framework-agnostic. If you swap the persistence adapter or the framework, your business logic breaks. The Root Cause: Mixing Business Boun...