We are React-ing Wrongly
summary
Argues that useMemo and useCallback are widely overused and shows benchmarks: list render demos at 100 and 1,000 items where per-render time difference is only ~0.4–0.6 ms, while the memoized version costs ~13 ms on first render vs ~3.8 ms for non-memoized. Calls out vague docs ("might make sense"), raises memory/GC concerns for cached values, recommends pass a function to the state setter to avoid stale closures, avoid lifting state or context unnecessarily, and prefer focused state libraries and TanStack-style data fetching for real performance gains.
AI-written summary · about
chapters (11)
- 0:00Introduction
- 2:11React’s evolution and state
- 7:56Overusing useMemo and useCallback
- 11:10Live demo: memo vs no memo
- 19:53How useCallback works
- 23:09Invalidation issues with useCallback
- 27:04useEffect and state pitfalls
- 29:34React render cycle and state lifting
- 31:21Memoization best practices
- 32:47When not to memoize
- 33:31Q&A
