The Hook Model
Hooks replaced class components' lifecycle methods with a composable, function-based API. useState manages local state. useEffect synchronizes with external systems. useRef persists values across renders without triggering re-renders. Understanding when React re-renders — and how to prevent unnecessary re-renders — is the foundation of performant React.
Custom Hooks
Custom hooks are the React pattern for code reuse. Any function that calls other hooks is a hook. Extract repeated stateful logic — data fetching, form handling, media queries, WebSocket connections — into custom hooks. The naming convention (use prefix) tells React's linter to apply hook rules.
Performance: useMemo, useCallback, memo
useMemo memoizes expensive computations. useCallback stabilizes function references to prevent child re-renders. React.memo prevents a component from re-rendering when its props haven't changed. The trap: overusing these adds complexity and memory overhead. Profile first with React DevTools, then memoize specific bottlenecks.
State Architecture
For complex state, useReducer gives you Redux-like predictability without the boilerplate. For global state that doesn't change frequently (theme, auth, locale), Context + useReducer is sufficient. For frequently-updated global state (server data, real-time feeds), reach for a dedicated library like Zustand or Jotai.
Conclusion
Hooks are simple primitives that compose into powerful patterns. Master useState, useEffect, and useRef first. Then learn when custom hooks provide the right abstraction. Add useMemo and useCallback only where profiling reveals a genuine bottleneck.