A Look Behind the Scenes of React & Optimization TechniquesEntry 9 of 10

The React Compiler

A build-time tool that automatically memoizes components, values, and functions, so manual memo(), useMemo, and useCallback are rarely needed.

react.devuseCallbackuseMemomemo

Notes

  • The React Compiler reached a stable release in late 2025. It's a separate build plugin (Babel-based), not part of the React runtime.
  • It analyzes components and inserts memoization where it's safe, based on the Rules of React (pure components, no mutation of props or state, Rules of Hooks).
  • Code that breaks those rules is skipped rather than optimized, so writing pure components matters even more.
  • Existing memo()/useMemo/useCallback calls keep working alongside it.
  • Setup depends on the build tool; follow the official guide at react.dev/learn/react-compiler.

Angular

No equivalent is needed. Signals and computed() already give Angular fine-grained, cached updates by design.

Quick reference

ReactAngular
React Compiler auto-memoizesSignals + computed() by design
Manual memo/useMemo/useCallback optionalNot applicable