When an established e-commerce platform approached us, their Lighthouse performance score had dropped to 34. Page load times exceeded 8 seconds on mobile, and their Core Web Vitals were consistently failing. Customers were abandoning carts, and their search rankings were declining.
The site had accumulated years of unoptimized images, render-blocking scripts, and inefficient database queries. Third-party tracking scripts alone added over 2MB to the initial page load. The team had tried quick fixes, but without a systematic approach, improvements were marginal.
We conducted a comprehensive performance audit covering every aspect of the site: server response times, asset delivery, rendering pipeline, and third-party script impact. Our optimization plan targeted the highest-impact issues first:
- Converted all images to WebP/AVIF with responsive srcsets
- Implemented code splitting and tree shaking, reducing JS bundle by 68%
- Set up CDN caching with optimized cache headers
- Deferred non-critical third-party scripts
- Optimized database queries, eliminating 23 N+1 query patterns
Within two weeks, the Lighthouse score jumped from 34 to 92. Largest Contentful Paint dropped from 8.2s to 1.4s, and Cumulative Layout Shift went from 0.42 to 0.03. The site passed all Core Web Vitals thresholds, and within a month, organic traffic increased by 23%.
The difference was night and day. Our site finally feels fast, and we've seen a measurable increase in conversions since the optimization.
— Head of Digital, E-Commerce Client