architecture-patterns

Structure backend projects by enforcing Domain, Application, and Infrastructure layering with explicit boundaries. This clean architecture approach uses domain entities, use cases, and swappable adapters through ports and connectors to ensure maintainability and testability.

Hexagonal architecture enables swappable implementations via ports and adapters for testing, while Domain-Driven Design focuses on modeling complex domain logic with domain entities and use cases. Both patterns combine to enforce consistent structure and naming for scalable applications.

You need SOLID principles and Dependency Inversion (DIP) when building large frontend apps or backend projects requiring layered organization, testability, and scalability. They enable swappable adapters and enforce separation between domain, application, and infrastructure layers.

Apply domain-driven design patterns to a new feature by following domain/application/infrastructure layering. Use AGENTS.md signals and practical checklists to guide incremental adoption of use cases, domain entities, and swappable adapters.

Clean architecture works for both large frontend applications and backend projects. It provides practical frontend examples and backend guidance for layered organization, ensuring testability, swappable adapters, and consistent structure across complex domain logic.

Use ports and adapters to enable swappable implementations for testing and integration. This hexagonal approach decouples infrastructure from domain logic, enforcing explicit boundaries and consistent structure while improving software maintainability and scalability.