When building modern apps, performance matters as much as functionality. A snappy UI improves user experience, retention, and trust. Here are some practical techniques I use in real projects, along with code snippets you can apply right away.
1. Prevent Unnecessary Re-renders
Every time props or state change, React re-renders. That’s fine—until components re-render without changes.
✅ Use React.memo
👉 This avoids re-rendering unless name or email actually change.
✅ Memoize Callbacks & Values
👉 useMemo avoids recalculating the filter, and useCallback keeps the function stable.
2. Optimize Large Lists
Big lists = big performance hits.
✅ Virtualize with react-window
👉 Only the items in view are rendered, making huge lists smooth.
3. Lazy Load Components
Why load heavy components before users need them?
👉 Components load only when needed, reducing initial bundle size.
4. Manage State Smartly
Global state re-renders everything that consumes it. Keep things local when possible.
👉 Don’t push this into Redux/Context unless multiple components truly need it.
5. Optimize Heavy Computations
Some calculations are expensive—don’t redo them on every render.
👉 useMemo makes sure it runs only when data changes.
6. Bundle Size Matters
Every KB counts. I confess that that I used this only once in a chatbot that was injected in others and it really mattered.
- Import only what you need:
- Analyze bundles with
@next/bundle-analyzeror Webpack tools. - Prefer native APIs (e.g.,
URLSearchParams).
7. Server-Side Rendering & Static Generation
Using Next.js:
9. 🔮 The Future: React Compiler
One exciting development is the upcoming React Compiler. Its goal is to automatically optimize components by analyzing dependencies and preventing unnecessary re-renders — without requiring us to manually wrap everything in useCallback or useMemo.
That means in the future, patterns like this:
…may no longer be necessary. The compiler will handle these optimizations automatically.
👉 Until it’s stable and widely available, we still need to apply techniques like React.memo, useMemo, and useCallback. But with React Compiler on the horizon, performance optimization in React will become much more seamless.
👉 Great for SEO and first-load performance.
⚡ Final Thoughts
Performance is about measuring first, then applying the right fix. Start with:
React.memo+ memoized callbacks- Virtualized lists
- Lazy loading heavy code
- Profiler analysis
These techniques keep apps fast, fluid, and delightful ✨.