React Patterns Performance and composition patterns for React 19 + Vite + Cloudflare Workers projects. Use as a checklist when writing new components, a review guide when auditing existing code, or a refactoring playbook when something feels slow or tangled. Rules are ranked by impact. Fix CRITICAL issues before touching MEDIUM ones. When to Apply - Writing new React components or pages - Reviewing code for performance issues - Refactoring components with too many props or re-renders - Debugging "why is this slow?" or "why does this re-render?" - Building reusable component libraries - Code r…