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name: react description: React development patterns and best practices including hooks, state management, and performance optimization. globs: ["/*.jsx", "/.tsx", "**/next.config.", "**/vite.config.*"] priority: 95 tags: ["framework"]

React Best Practices

Component Design

• Keep components small and focused (< 200 lines)
• Prefer functional components with hooks
• Use composition over prop drilling
• Lift state only when needed
• Co-locate related code

Hooks

• Use useState for local state
• Use useEffect for side effects (with cleanup)
• Use useCallback for stable function references
• Use useMemo for expensive computations
• Use useRef for mutable values
• Always include all dependencies in dependency arrays
• Create custom hooks for reusable logic

Performance

• Use React.memo for expensive pure components
• Lazy load routes with React.lazy
• Use Suspense for loading states
• Use keys properly in lists (never use index as key)
• Avoid inline object/function creation in JSX
• Use React DevTools Profiler

State Management

• Start with local state + prop drilling
• Use Context for theme/auth/locale
• Use Zustand/Jotai for simple global state
• Use React Query/TanStack Query for server state
• Use Redux Toolkit for complex client state

Patterns

• Container/Presentational components
• Compound components for flexibility
• Render props for sharing logic
• Custom hooks for logic reuse