backend-dev-guidelines

# Backend Development Guidelines ## Purpose Establish consistency and best practices across backend microservices (blog-api, auth-service, notifications-service) using modern Node.js/Express/TypeScript patterns. ## When to Use This Skill Automatically activates when working on: - Creating or modifying routes, endpoints, APIs - Building controllers, services, repositories - Implementing middleware (auth, validation, error handling) - Database operations with Prisma - Error tracking with Sentry - Input validation with Zod - Configuration management - Backend testing and refactoring --- ## Quick Start ### New Backend Feature Checklist - [ ] **Route**: Clean definition, delegate to controller - [ ] **Controller**: Extend BaseController - [ ] **Service**: Business logic with DI - [ ] **Repository**: Database access (if complex) - [ ] **Validation**: Zod schema - [ ] **Sentry**: Error tracking - [ ] **Tests**: Unit + integration tests - [ ] **Config**: Use unifiedConfig ### New Microservice Checklist - [ ] Directory structure (see [architecture-overview.md](architecture-overview.md)) - [ ] instrument.ts for Sentry - [ ] unifiedConfig setup - [ ] BaseController class - [ ] Middleware stack - [ ] Error boundary - [ ] Testing framework --- ## Architecture Overview ### Layered Architecture ``` HTTP Request ↓ Routes (routing only) ↓ Controllers (request handling) ↓ Services (business logic) ↓ Repositories (data access) ↓ Database (Prisma) ``` **Key Pri...