Node.js/Express/TypeScript microservices development patterns. Use when workingwith backend code: routes, controllers, services, repositories, middleware, APIs.Covers:- Layered architecture (routes → controllers → services → repositories)- Express routing and middleware patterns- Prisma database access and ORM best practices- Zod validation and input sanitization- Sentry error tracking integration- BaseController pattern and dependency injection- Async/await patterns and error handling- Testing strategies and performance monitoring