Asda: Scan & Go, rebuilt mid-flight

Asda: Scan & Go, rebuilt mid-flight

Millions of shoppers scanning their own baskets, on hardware the accountants chose, through a platform being rebuilt underneath them.

The problem

After Walmart sold Asda, Scan & Go had to leave Walmart's infrastructure without shoppers noticing. New backend, new cloud, same tills open every morning.

What we built

The in-store experience end to end: the React Native handset and customer apps, the supporting Node/TypeScript services on Azure Functions, and a React kiosk managing device release on the shop floor, with real-time state flowing over Azure Web PubSub.

And the second engagement

The first one. Asda originally brought us in to change how the team worked: a proper delivery pipeline, automated end-to-end testing with Detox, and the memory-leak hunt that made the app survive all day on low-spec in-store handsets. Culture first, rebuild second.