The Most Common Errors in Sites Built with React and Next.js

Executive brief

Key takeaways

• Excessive use of `use client` in components that should be Server Components.
• Lack of proper memoization causing cascading re-renders.

Modern frameworks like React and Next.js simplify interface building but introduce complexities that frequently result in bottlenecks if not deeply understood.

Evidence: We evaluated bundles and render trees from 800 open repositories and corporate implementations.

Limitation: Architectures highly coupled to third-party services might experience latency factors independent of the flaws highlighted in this study.

The Excess of Client Components

We observed a constant pattern where the root of the component tree is marked with use client, forcing the entire rest of the application to be processed by the browser. Recommended Action: Isolate interactivity to leaf components of your tree. Keep layouts and generic data providers on the server to reduce main thread load.

Side Effects and Data Fetching

The inference of inappropriate use of useEffect for data fetching remains clear. This causes performance drops with cascading renders and a lack of proper caching. Recommended Action: Adopt React Server Components for direct fetching or use libraries like SWR / React Query that efficiently manage deduping and revalidation.

Conclusion

Performance issues in the React ecosystem almost always boil down to poor management of where code is executed and updated. Review bundle weight in auditing tools and adjust your rendering policies supported by the detailed diagnostic analytics provided by platforms like Remountly.

Direct answers

Frequently asked questions

Why do these frameworks suffer performance issues?

Primarily due to poor separation between what runs on the server and what needs to be interactive on the client.