How We Cut a SaaS App’s Page-Load Time From 6.4s to 1.2s

<p>When a B2B SaaS client came to us with a 6.4-second First Contentful Paint, every customer touchpoint was suffering. After 3 weeks of focused work, we got their median page load down to 1.2s.</p><h2>The diagnostic</h2><p>We started with Lighthouse, WebPageTest, and Chrome DevTools profiling. The biggest culprits: 4MB of unoptimized hero images, blocking third-party scripts, and a chatty REST API requiring 12 round trips on first paint.</p><h2>The fixes that mattered</h2><ol><li>WebP/AVIF with responsive <code>srcset</code> — saved 2.8MB on first load.</li><li>Defer non-critical JS, preload critical CSS — cut TBT by 70%.</li><li>Bundled the 12 API calls into a single GraphQL query — cut server round trips by 90%.</li><li>Edge caching with Cloudflare for the marketing pages — TTFB went from 800ms to 60ms.</li></ol><h2>The business outcome</h2><p>Conversion rate climbed 28% in the four weeks following deploy. Bounce rate dropped from 62% to 41%.</p>