react-concurrency-and-memoization

Fix a slow React UI by wrapping non-urgent updates in a startTransition block using useTransition, which prioritizes urgent interactions while deferring expensive filtering work to keep the main thread responsive.

Use useMemo and useCallback in React only after profiling with React DevTools confirms expensive renders or referential equality issues, avoiding premature optimization and unnecessary re-renders across component trees.

useTransition prioritizes urgent updates by deferring non-urgent state updates inside startTransition, while useDeferredValue smooths the UI by progressively updating deferred content, ideal for receiving expensive values from parent components.

Prevent unnecessary re-renders in React 18+ by applying React.memo to components and ensuring referential equality for props, combined with systematic concurrency strategies to schedule rendering work smartly.

React.memo works with concurrent rendering features to optimize performance by skipping re-renders when props are referentially equal, while useTransition and useDeferredValue schedule the actual rendering work.

Your React app may lag because memoization was applied prematurely without profiling, or because referential equality is broken, meaning you must profile with React DevTools to verify the actual bottleneck before optimizing.