axum-service-architecture

Layered architecture in Axum separates routing, business logic, and data access into distinct Router, Handler, Service, and Repository layers. This pattern improves testability and maintainability by enforcing clear separation of concerns and making dependencies explicit.

Use AppState with FromRef to inject dependencies directly into handlers. This approach avoids global state, keeps dependencies explicit, and enables testable handler functions that declare their requirements upfront.

Build a deterministic middleware stack using Tower ServiceBuilder to layer observability, timeouts, retries, compression, and CORS in a predictable order. This ensures production-grade concerns apply consistently across your service.

Organize routers modularly by domain or feature module, then compose them together at the top level. This approach keeps API routes grouped logically and makes the codebase easier to navigate as services scale.

Yes, the layered architecture integrates Tower middleware composition for timeouts, tracing, and other cross-cutting concerns. The pattern satisfies functional requirements for production-grade middleware stacks alongside clean separation of logic.

Separating these layers isolates concerns: handlers manage HTTP semantics, services encapsulate business logic, and repositories handle data access. This enables testing each layer independently and makes logic reusable across multiple endpoints.