Frontend Performance: From Seconds to Milliseconds
Performance isn't a feature—it's a requirement. A slow website is a bad user experience, period.
Measuring Performance
Before you optimize, measure. We use:
- Google Lighthouse
- WebPageTest
- Custom RUM (Real User Monitoring)
Quick Wins
1. Image Optimization
JPEG quality 75% + WebP format = 80% size reduction in most cases.
2. Code Splitting
Splitting your JavaScript bundle is non-negotiable. Users shouldn't download code for features they don't use.
3. Caching Strategy
Cache headers are free performance. Invest in getting them right.
4. Minification and Compression
Gzip compression gives you 60-70% file size reduction for text.
Advanced Techniques
- Resource hints (dns-prefetch, preconnect, prefetch)
- Service Workers for offline capability
- Web Workers for heavy computation
- Virtual scrolling for large lists
The Metrics That Matter
- LCP (Largest Contentful Paint): When can users see content?
- FID (First Input Delay): Is the site responsive?
- CLS (Cumulative Layout Shift): Does the page jump around?
Our Results
By applying these techniques systematically, we reduced our initial page load from 4.5 seconds to 1.1 seconds.
The Takeaway
Frontend performance is not optional. It affects user retention, SEO, and business metrics. Treat it with the seriousness it deserves.