clean-architecture

Clean architecture layer boundaries are enforced by mapping components to four layers—Domain, Use Case, Interface Adapters, and Infrastructure—and ensuring dependencies point inward. This skill validates that Repository Interfaces reside in the Use Case layer while implementations live in Interface Adapters.

Repository Interfaces belong in the Use Case layer, while Repository and Gateway Implementations reside in the Interface Adapters layer. This separation maintains clean architecture principles by keeping dependency directions pointing toward the domain.

Run an architecture review checklist by mapping existing project components to the four clean architecture layers and validating layer responsibilities. This skill guides the review to ensure Infrastructure only hosts cross-cutting concerns like logging and configuration.

Clean architecture is suitable for domain-driven design projects requiring clear separation among Domain, Use Case, Interface Adapters, and Infrastructure layers. It provides a reference model for evaluating existing architectures and aligning future designs with architectural principles.

Infrastructure layer should only host cross-cutting concerns such as logging, configuration, and metrics. When domain logic or persistence code appears in Infrastructure, it violates clean architecture principles and must be moved to the Domain or Interface Adapters layer.

The best way to structure a layered architecture for maintainability is applying a four-layer clean architecture model. This disciplined structure separates Domain, Use Case, Interface Adapters, and Infrastructure so teams can reason about dependencies and testability.