architecture-patterns

Implement Clean, Hexagonal, and DDD patterns for maintainable, testable, and scalable backend systems.

• Clean Architecture: layers with dependencies flowing inward
• Hexagonal Architecture: domain core separated from infrastructure
• Domain-Driven Design: aligns software with business domain

• Dependencies point inward (inner layers independent)
• Business logic isolated from frameworks and databases
• Easy testing via mockable interfaces and ports
• Supports technology changes without code changes
• Enables loose coupling and high testability
• Promotes scalability and maintainability
• Facilitates team onboarding and standards alignment

1. 1.Apply when designing new systems or refactoring monoliths
2. 2.Structure code with clear layer separation (domain → adapters → infrastructure)
3. 3.Define interfaces first, implement adapters later
4. 4.Ensure business rules are in domain, not in infrastructure