Lazy Loading, Code Splitting, and Image Optimization for SaaS Applications

TL;DR Lazy loading defers offscreen resources: Use loading="lazy" for images and iframes. For custom elements, use Intersection Observer to load content just before it enters the viewport. Add placeholder skeletons to prevent layout shifts. Code splitting reduces initial bundle size: Split by route (React lazy() ) so users download only what they need. Split heavy components (charts, editors) to load on demand. Use vendor splitting to separate library code for better caching. Optimize images at