Building Performant React Apps: A Deep Dive

Performance isn't just about speed — it's about creating experiences that feel instant and delightful. In this post, I'll share the key techniques I use to build React apps that score 95+ on Lighthouse.

1. Code Splitting Done Right

The most impactful optimization is ensuring users only download the code they need. Next.js gives us route-based splitting for free, but we can go further with dynamic imports for heavy components.

import dynamic from 'next/dynamic';

const HeavyChart = dynamic(() => import('./HeavyChart'), {

loading: () => <ChartSkeleton />,

ssr: false,

});

2. Memoization Strategies

Not every component needs `React.memo`, but knowing when to use it makes a huge difference. Focus on components that:

3. Image Optimization

Always use Next.js Image component. It handles lazy loading, WebP conversion, and responsive sizing automatically. This alone can improve your LCP by 40%+.

4. State Management

Keep server state and client state separate. Use React Query or SWR for server state, and keep client state minimal and close to where it's used.

Conclusion

Performance is a feature. By applying these patterns consistently, you can build apps that feel instant and keep users engaged.