An SEO-first SPA framework rolled out across home-improvement giants

Kingfisher wanted its brands on a modern, component-driven frontend — a single SPA-style framework reused across B&Q, Screwfix, and Castorama. The obvious risk: rolling an SPA over three high-traffic, search-dependent eCommerce sites without nuking organic visibility.

These are hundreds of millions of pounds of organic revenue per brand. "SEO-safe SPA" isn't a slogan — it's an engineering requirement.

• Defined the rendering contract: server-side rendering as the default for any URL Google was expected to index, with progressive hydration for interactivity. No route that mattered to search was allowed to be CSR-only.
• Designed URL, canonical, and pagination patterns that worked identically across brands and markets — so migrations could be compared apples-to-apples and regressions spotted quickly.
• Specified the internal linking model: breadcrumbs, category hubs, related-product modules, and editorial content — all driven by the same data layer across brands.
• Embedded SEO acceptance criteria into the component library and release pipeline: renderability tests, canonical/meta coverage, structured data validation, and Core Web Vitals budgets enforced at build time.
• Ran crawl diff analysis on every major release — before/after against the reference crawl — so regressions were caught before they shipped to production search surfaces.

Making rendering a first-class architectural decision — rather than a later retrofit — was the whole game. Once SSR was the default and acceptance criteria lived inside the component library, the framework became self-policing: teams couldn't accidentally ship CSR-only indexable routes.

Treating all three brands as one platform multiplied the payoff: any fix, optimisation, or schema rollout landed across the portfolio.

The framework became the group's standard for customer-facing surfaces across three flagship brands. SEO stayed a first-class concern through a major frontend modernisation — the kind of migration that usually shaves 20–40% off organic visibility.