Performance Optimization Techniques

Web performance directly impacts user experience and business metrics. Here are key optimization strategies.

Core Web Vitals

Google's Core Web Vitals are a set of specific factors that Google considers important in a webpage's overall user experience.

Largest Contentful Paint (LCP)

Measures loading performance:

import Image from 'next/image';

const optimizedImage = (
  <Image
    src="/hero-image.jpg"
    alt="Hero image"
    width={800}
    height={600}
    priority
    placeholder="blur"
    blurDataURL="data:image/jpeg;base64,..."
  />
);

First Input Delay (FID)

Measures interactivity:

const HeavyComponent = lazy(() => import('./HeavyComponent'));

function App() {
  return (
    <Suspense fallback={<div>Loading...</div>}>
      <HeavyComponent />
    </Suspense>
  );
}

Cumulative Layout Shift (CLS)

Measures visual stability:

Warning: Always specify dimensions for images and videos to prevent layout shifts.

Bundle Optimization

// Import only what you need
import { debounce } from 'lodash/debounce';

Memory Management

Common memory leak sources: Event listeners, timers, and closures holding references to large objects.

useEffect(() => {
  const handleResize = () => {
    setWindowSize({ width: window.innerWidth, height: window.innerHeight });
  };

  window.addEventListener('resize', handleResize);

  return () => {
    window.removeEventListener('resize', handleResize);
  };
}, []);

Monitoring: Use tools like Lighthouse, Web Vitals, and performance profilers to continuously monitor your application's performance.