Modern React Patterns and Performance

Introduction

React has evolved significantly over the years. Modern React patterns focus on performance, maintainability, and developer experience. Let's explore the patterns that define contemporary React development.

Hooks and Custom Hooks

React Hooks revolutionized how we write components by enabling state and side effects in functional components.

useCallback for Performance

const memoizedCallback = useCallback(
  (a) => {
    doSomething(a);
  },
  [a],
);

Use useCallback to memoize functions that are passed as dependencies to other hooks or used as event handlers.

useMemo for Expensive Computations

const memoizedValue = useMemo(
  () => computeExpensiveValue(a, b),
  [a, b]
);

Cache expensive computations and avoid recalculating them on every render.

Concurrent Rendering

React's concurrent features allow the library to interrupt long renders to keep the application responsive.

Suspense

Suspense lets your components "wait" for something before rendering.

<Suspense fallback={<Loading />}>
  <LazyComponent />
</Suspense>

Server Components

React Server Components allow rendering components on the server and streaming the result to the client.

// This runs only on the server
async function BlogPosts() {
  const posts = await fetch('https://...');
  return <BlogPostList posts={posts} />;
}

Performance Best Practices

• Keep components small and focused
• Use code splitting and lazy loading
• Avoid unnecessary re-renders with memoization
• Optimize images and assets
• Use a production build for deployment

Conclusion

Modern React development is about understanding the tools available and using them appropriately. Focus on user experience, maintain clean code, and always measure performance improvements.