Backend Development Overview Server-side development patterns, frameworks, and best practices for building scalable APIs and services. --- Express.js Application Structure Middleware Patterns Error Handling --- NestJS Module Structure DTOs with Validation Services with Dependency Injection --- Database Integration Prisma ORM Transactions --- Background Jobs Bull Queue --- WebSockets --- Related Skills - [[api-design]] - API design patterns - [[database]] - Database patterns - [[security-practices]] - Backend security --- Sharp Edges（常見陷阱） 這些是後端開發中最常見且代價最高的錯誤 SE-1: 未處理的 Promise Rejection - 嚴重度…