Modern Web Performance: Beyond the Basics

Performance optimization has evolved significantly. Gone are the days when minifying JavaScript was enough. Let’s explore modern techniques that actually move the needle.

Core Web Vitals: What Actually Matters

Google’s Core Web Vitals have become the north star for performance:

• LCP (Largest Contentful Paint): Optimize your hero images and fonts
• FID (First Input Delay): Break up long JavaScript tasks
• CLS (Cumulative Layout Shift): Reserve space for dynamic content

The Real Performance Killers

After profiling hundreds of web apps, these are the most common issues:

1. Third-party scripts: Analytics, chat widgets, and ads can add 2-3 seconds
2. Unoptimized images: WebP and AVIF can reduce size by 50-80%
3. Font loading: Use font-display: swap and preload critical fonts
4. JavaScript bundles: Code splitting and tree shaking are essential

Edge Computing Changes Everything

Moving computation closer to users with edge functions can dramatically reduce latency:

// This runs at the edge, close to your users
export default {
  async fetch(request) {
    const response = await fetch(request);
    // Customize response based on user location
    return new Response(response.body, {
      headers: { 'Cache-Control': 'public, max-age=3600' }
    });
  }
}

The future of web performance is at the edge.