Speed directly impacts conversion rates.
Image optimization:
- Serve responsive images
- Use modern formats (WebP, AVIF)
- Lazy load below-fold images
- Preload hero image
Code optimization:
- Code split reviews and related products
- Defer non-critical JavaScript
- Inline critical CSS
Caching:
- Cache product data with short TTL
- CDN for static assets
Metrics to track: LCP (hero image), FID (add to cart responsiveness), CLS (image placeholders).