Backend Patterns

**Quick judgement:** This skill is a strong, practical collection of backend patterns for Node.js/Express/Next.js, with solid coverage of API design, data access, performance, auth, and operational concerns. It is well-suited as a reference or template set for small-to-medium services, especially when using Next.js API routes, Supabase, and Redis. **Recommended scenarios:** - You’re building or refactoring a Node/Next.js backend and want standard patterns (repository/service layers, middleware, centralized errors). - You need examples for caching (Redis, cache-aside), N+1 prevention, and query optimization. - You want ready-made snippets for JWT auth, RBAC, rate limiting, job queues, and structured logging. - You’re onboarding junior/mid-level backend developers and need concrete examples of “good vs bad” backend design. **Key strengths:** - Concrete, idiomatic TypeScript/Node examples that can be dropped directly into real projects. - Emphasizes separation of concerns (repository vs service layer, middleware, decorators/wrappers). - Covers critical production topics: transactions, retries with exponential backoff, rate limiting, background jobs, logging. - Clear REST conventions and practical Supabase usage (RPC for transactions, column selection, etc.). **Risks / limitations:** - Several patterns (in-memory rate limiter, in-memory job queue) are simplified and not suitable as-is for horizontally scaled or highly reliable production systems. - Security and robustness concerns are implied but not deeply treated (e.g., no detailed input validation strategy beyond a Zod example, no discussion of secret management, CSRF, or multi-tenant authorization). - Supabase- and Next.js-specific samples may need adaptation for other stacks or runtimes. **Best fit:** Use this skill as a **pattern cookbook and starting point** for backend design in Node/Next.js, then harden and extend the patterns (distributed rate limiting, durable queues, stricter validation, more advanced auth) for high-scale or security-critical environments.