A regulated utility in the UK faced a compliance nightmare: its online service form ran on an aging ASP page while a recent React rewrite crashed after three days of user complaints. The failed build stored images in localStorage, hit a 5 MB cap and broke accessibility standards, threatening fines for dropping satisfaction below 96 % and could incur large penalties immediately.

The contractor’s team handed the project to a senior developer who rebuilt the wizard with Astro, delivering an HTML‑first site where JavaScript lives only in web components for progressive enhancement. Each step renders as a separate page, submits to the backend, and preserves a unique session ID, satisfying WCAG AA and allowing completion on legacy browsers and 3G links for users.

A custom validation‑enhancer web component wrapped the native form, intercepting HTML5 checks, surfacing errors via ARIA attributes and falling back to browser validation when JavaScript failed. The lightweight solution added under 1 KB of code yet doubled completion rates, even surfacing users who resumed a month later. The result proved that an HTML‑first approach can rescue public‑service portals without costly rewrites.