From 4s to 1.2s LCP: a Next.js performance audit
A step-by-step LCP / INP / CLS breakdown with the diffs that mattered, the ones that didn't, and a Lighthouse score that survived.
A SaaS dashboard came to us with a 4.1s LCP and a Lighthouse perf score of 41. Six weeks later it was at 1.2s and 98 — and we kept the same product surface, the same component library, and the same CMS.
The audit covered streaming SSR, partial pre-rendering, image optimization at the edge, font loading strategy, third-party script auditing, and a relentless focus on the critical rendering path. We share what moved the needle, what looked promising but didn't, and the regressions we caught before they shipped.
Naveen Reddy
Principal Engineer
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