Optimizing Cursor-Generated Code for Performance

Cursor apps commonly suffer from unnecessary client-side rendering — components marked with 'use client' that could be server components, forcing the browser to download and execute JavaScript that could have been rendered on the server. Bundle sizes are often large because Cursor imports entire libraries (e.g., all of lodash) instead of specific functions. Re-renders cascade through the component tree because props are new object references on every render

Audit each 'use client' directive — remove it from components that don't use hooks, event handlers, or browser APIs. Replace full library imports with tree-shakeable alternatives. Add React.memo to expensive list items and useMemo/useCallback where profiling shows impact. Implement Next.js Image component for image optimization. Add loading.tsx files for route segments to improve perceived performance

Before optimizing, measure. Use your browser's Lighthouse audit to get a baseline score. Check Core Web Vitals (LCP, FID, CLS) — these directly affect your Google ranking. Use the Performance tab in DevTools to identify which components take the longest to render. For server-side performance, add timing logs to API routes to find slow endpoints.

The fastest way to improve performance: optimize and lazy-load images, enable compression on your server, remove unused CSS and JavaScript, implement code splitting so users only download code for the page they're viewing, and add proper caching headers for static assets. These changes alone can cut load times significantly.

If your Cursor app uses a database, slow queries are often the biggest performance bottleneck. Add indexes on columns you filter or sort by. Use SELECT to fetch only the columns you need instead of SELECT *. Implement pagination for lists — loading 10,000 rows at once will always be slow. Consider adding a caching layer for data that doesn't change frequently.