React Compiler + Vite: Drop useMemo and useCallback

If you have ever sprinkled useMemo and useCallback across a React codebase just to silence re-renders, you know the cost: noisier components, brittle dependency arrays, and reviews that argue about whether a given memo is worth its weight. The React Compiler changes that contract. It is now stable, ships as a Babel/SWC plugin and a Vite integration, and it auto-memoizes the right things at build time so your runtime code stays simple.

This guide takes you from a blank Vite project to a production-grade React 19 app with the compiler turned on, ESLint enforcing the Rules of React, and a measurable drop in re-renders. It targets intermediate React developers comfortable with hooks; no compiler internals required.