React performance optimization is about knowing when and where to optimize. Premature optimization is the root of all evil, but strategic memoization can make a real difference in complex applications.
useMemo and useCallback
These hooks prevent unnecessary recalculations and re-renders. useMemo caches computed values, while useCallback caches function references. Use them when passing callbacks to optimized child components or performing expensive calculations.
When to Optimize
Measure first, optimize second. React DevTools Profiler will show you exactly which components re-render and why. Focus on components that render frequently with expensive operations, not every component in your tree.