React Design Patterns: Hooks, Context, and State Management

Scale React apps with predictable patterns and strong boundaries.

Executive summary

• Hoist state thoughtfully; collocate where possible; isolate where needed
• Prefer custom hooks + context boundaries over global stores by default
• Use state machines for complex flows; memoize carefully; measure

Controlled components

• Single source of truth; embrace value/onChange pairs; derive state when possible

Custom hooks

export function useDebounced<T>(value: T, ms = 250) {
  const [v, setV] = useState(value)
  useEffect(() => { const t = setTimeout(() => setV(value), ms); return () => clearTimeout(t) }, [value, ms])
  return v
}

Context boundaries

• Keep contexts small and stable; split read vs write contexts; avoid rerender storms

State machines

• XState or lightweight reducers for multi-step flows and async effects

Performance

• React.memo, useMemo/useCallback; list virtualization; RSC for server work

Testing

• Unit hooks; integration components; contract tests for context

FAQ

Q: Redux or context?
A: Start with hooks + context; add Redux/Zustand for cross-cutting global state with tooling.