Complete guide to the layered architecture pattern used in backend microservices. Each layer can be tested independently Changes isolated to specific layers Bus
This skill provides a comprehensive overview of the layered architecture pattern used in backend microservices, emphasizing clear separation of concerns across routes, controllers, services, repositories, and middleware. It breaks down the request lifecycle from HTTP entry to database interaction, illustrating how each layer operates independently while collaborating to handle requests efficiently. The guide also compares service implementations, highlighting best practices and common pitfalls in structuring microservice codebases.
This skill is designed for backend engineers working closely with performance marketing platforms who need scalable, maintainable APIs. It suits growth leads overseeing technical teams responsible for building or optimizing microservices that support marketing automation, analytics, or CRM integrations. Agency strategists managing technical audits or recommending API improvements will also benefit from understanding how layered architecture patterns promote reliable feature delivery and testing.
Practitioners start by mapping the request lifecycle, following an HTTP call through middleware, routing, controller validation, service business logic, and repository database operations. Next, they analyze existing services to identify layering strengths and weaknesses, such as spotting where business logic improperly resides in routes or where naming conventions break consistency. Finally, they organize or refactor codebases by separating concerns into dedicated directories—routes strictly for registration, controllers for request handling, services for business logic, repositories for data access, and middleware for cross-cutting concerns—enabling isolated testing and easier maintenance.
How do I ensure business logic is not mixed into routes? Keep routes focused on delegation and validation, moving all core logic into service classes. What naming conventions improve code clarity? Use PascalCase with descriptive suffixes like Controller, Service, or Repository for consistency and discoverability. How do middleware layers affect request handling order? Middleware must be registered in the correct sequence, with error handlers placed after routes to catch downstream errors effectively.
Attach this skill to any Metaflow agent task that involves backend service design or codebase review to guide architectural decisions and improve service reliability. Expect clear, step-by-step guidance on dissecting layered backend code and applying best practices for maintainability and testability. This skill pairs well with tasks focused on API optimization, enabling actionable insights on structuring microservices for performance and scalability.
For broader context, see our roundup of claude marketing skills, and read common Claude Code content mistakes for related setup guidance.