Rust Patterns

Production FastAPI patterns with Pydantic v2, async endpoints, OAuth2/JWT, dependency injection, testing, and Kubernetes deployment

Production Go concurrency patterns — goroutines, channels, sync primitives, context, worker pools, pipelines, and graceful shutdown. Use when building concurrent Go applications or debugging race conditions.

Write and run tests across languages and frameworks. Use when setting up test suites, writing unit/integration/E2E tests, measuring coverage, mocking dependencies, or debugging test failures. Covers Node.js (Jest/Vitest), Python (pytest), Go, Rust, and Bash.

Write idiomatic Rust avoiding ownership pitfalls, lifetime confusion, and common borrow checker battles.

WHAT: Production-ready Node.js backend patterns - Express/Fastify setup, layered architecture, middleware, error handling, validation, database integration, authentication, and caching. WHEN: User is building REST APIs, setting up Node.js servers, implementing authentication, integrating databases, adding validation/caching, or structuring backend applications. KEYWORDS: nodejs, node, express, fastify, typescript, api, rest, middleware, authentication, jwt, validation, zod, postgres, mongod

Implement secure authentication and authorization using JWT, OAuth2, session management, RBAC, permissions, and resource ownership verification.