--- title: Case Study: Next.js Commerce Rebuild, 9s to 1.2s description: A storefront with eleven thousand products took nine seconds to become interactive on mobile. That single number was the entire brief for the replatform. canonical: https://www.hire-web-dev.com/work/velocity/ section: Case studies updated: 2026-09-11 author: SumanKumar Phuyal site: hire-web-dev.com note: >- Generated from the page of record at the canonical URL above. The four case studies are placeholder work and their metrics were never measured; imagery is AI-generated concept art. See https://www.hire-web-dev.com/disclosure/. --- # VELOCITY — COMMERCE AT SPEED A storefront replatform for a fashion retailer with eleven thousand products and a catalogue that changed hourly. The old site took nine seconds to become interactive on mobile. That number was the entire brief. ## The constraint Nine seconds to interactive, and a bounce rate that matched. The cause wasn't one thing, which is usual: four hundred kilobytes of JavaScript for a personalisation layer that affected two components, a product grid that fetched every variant of every item on first paint, and a tag manager loading eleven third-party scripts ahead of the page's own content. ## What I built Rendering moved to the edge, with product pages served from cache and revalidated on webhook rather than on a timer — a catalogue that changes hourly doesn't need a five-minute revalidation window, it needs to know precisely when something changed. Personalisation became a streamed hole in an otherwise static page, so the first paint never waited on a per-visitor lookup. The grid was rebuilt to fetch only what it renders: one variant per product, with remaining variants fetched on interaction. Third-party scripts were audited down from eleven to three, which was a political exercise more than a technical one, and the survivors were moved behind consent and idle callbacks so they could never compete with content. ## Result and regrets Time to interactive on mobile fell to 1.8 seconds. Largest contentful paint came in at 1.2 seconds at the 75th percentile of real traffic. JavaScript shipped to a product page dropped by roughly seventy per cent. Regret: I let the design system and the replatform run concurrently, so both moved slower than either would have alone. Sequencing them would have cost a month and saved two. ## Key facts - Year: 2024 - Role: Frontend lead - Stack: Next.js / Edge / Tailwind - Products: 11,400 ## Case file - Year: 2024 - Role: Frontend lead - TTI before: 9.0 s - TTI after: 1.8 s ## Topics NEXT.JS, EDGE RUNTIME, TAILWIND, SHOPIFY, CORE WEB VITALS ## Image ![Brushed chrome form streaking through dark space, treating speed as a material quality for a storefront](https://www.hire-web-dev.com/assets/img/velocity-chrome-form-speed-study.jpg)