Vercel React Best Practices

It covers 45 rules across eight categories, from eliminating request waterfalls and optimizing bundle size to managing re-renders and server-side caching patterns. The rules are prioritized by impact, so Claude knows to flag barrel imports and missing Promise.all before nitpicking loop optimizations. Use it when writing or reviewing React and Next.js code where performance actually matters. The specificity is the selling point here: instead of vague advice about memoization, you get concrete patterns like using React.cache for per-request deduplication or next/dynamic for code splitting heavy components.