react-best-practices

Start independent promises immediately and await them together with Promise.all(), or use better-all for partial dependency chains. In Server Components, restructure with component composition so sibling components fetch in parallel instead of sequentially.

Import directly from source files instead of barrel entry points, which can load thousands of unused modules. In Next.js 13.5+, enable optimizePackageImports in next.config.js to automatically transform barrel imports at build time.

React.cache() deduplicates calls within a single request, ideal for auth checks and database queries in one render pass. Use an LRU cache like lru-cache when data must persist across sequential requests, such as repeated user actions hitting multiple endpoints.

Yes, several rules specifically address RSC concerns: minimizing serialization at server-client boundaries, avoiding duplicate serialization of derived props, and parallelizing data fetching through component composition in async Server Components.

Common causes include subscribing to state only used in callbacks, wide effect dependencies, and unstable callback references. The re-render rules recommend deferring state reads, narrowing effect dependencies, using functional setState, and applying startTransition for non-urgent updates.

Avoid Suspense when data drives layout decisions, when content is SEO-critical above the fold, when queries are small and fast, or when layout shift from loading states harms the user experience more than the delayed initial paint.