
A strict 2026 MERN stack engineering playbook with comprehensive code examples for React, Node, Express, and MongoDB.
Use this skill when building, reviewing, or architecting MERN stack applications (MongoDB, Express, React, Node.js). Triggers include: questions about React component patterns, state management, data fetching, TypeScript setup, Express API design, Mongoose schema design, folder structure, auth patterns, performance, or any combination of these. Covers pragmatic production standards — what to use, what to skip, and why — across the full stack.