// 04 · work
Crown Oil Sustainability_
The sustainability hub for the UK’s first carbon-neutral fuel supplier, covering its Net Zero pledge and ESG framework, with a carbon calculator showing the carbon saved by switching from diesel to HVO.
- role
- Lead developer
- year
- 2022
- stack
- WordPress · PHP · TypeScript · Web Components · Vite · AWS · Cloudflare
- category
- Work
// GTmetrix, Nov 2026
93%
performance
98%
structure
512 ms
LCP
209 ms
TBT
0
CLS
Its calculators come from a set I built for the group, including a carbon calculator, a tank size calculator and volume converters. Each one is an HTML custom element, built once and embedded on whichever sites need it, and takes its colours from the theme of the site it’s on.
Like every site in the group, it’s a custom WordPress theme, front end and back end, built from scratch. It runs on a back-end library I wrote and share across all of the sites, which handles form submissions, phone and email verification and common utilities. Front-end assets are bundled with Vite, and the sites are hosted on AWS behind Cloudflare: I moved the whole group onto Cloudflare and tuned its caching, which made the sites far more reliable.