React Performance: Bundle Size — Dynamic Imports. Keywords: dynamic import lazy next. Platform: React/Next.js. Description: Use next/dynamic to lazy-load large components not needed on initial render. Do: Use dynamic() for heavy components. Don't: Import heavy components at top level. Good Example: const Monaco = dynamic(() => import('./monaco'), { ssr: false }). Bad Example: import { MonacoEditor } from './monaco-editor'. Severity: Critical.