E-commerce
Rebuilding a commerce site that loaded four times slower than its competitors
The old site took over eight seconds to show its main content on mobile. I rebuilt it and kept every existing URL.
Largest contentful paint down to 1.4 seconds
- Client
- Client asked not to be named
- Duration
- 3 months
- Engagement
- Fixed price
Context
Category pages took over eight seconds to show their main content on 4G. Product images were served at their original 3000-pixel size and scaled down by the browser, and each page pulled seventeen separate JavaScript files.
The owner had already paid two agencies to "optimise speed". Both had installed a caching plugin on top of the problem instead of fixing it.
What was built
I measured before touching anything. The performance trace put 71% of the wait on images, 22% on render-blocking JavaScript, and the rest on the server.
The rebuild used static rendering, with images converted to a modern format and cut to their display size. Every existing URL was preserved, and the few that had to change got 301 redirects, so no ranking was lost.
Data capture runs on a phone, at the place the work happens. The real user of this screen is standing up, busy and has one hand free, so it carries only the fields that are actually required.
Outcome
Largest contentful paint on 4G dropped from over eight seconds to 1.4 seconds. Core Web Vitals for category pages went from red to green.
Three months later search traffic was up rather than down, which usually does not happen after a rebuild, because no URL was lost.