About the bakery

Proof of Concept Bakery, “Proof of Concept” for short, is a neighborhood bakery in Salt Lake City. It does not exist.

The bakery

Its kitchen starts before dawn, and its counter is open from 07:00 to 15:00, Tuesday to Sunday; it is closed on Mondays. It sells breads, pastries, cakes, savory bakes and drinks, for pickup in 15-minute slots or delivery in 2-hour windows. On weekdays one van delivers a handful of orders; on Saturdays four vans make 63 stops. It caters breakfasts, pastry tables, lunches and celebrations at six venues, at most two events a day, booked at least a week ahead. It has 60 regular customers.

Nothing in it is real

Every customer, venue, address and card is synthetic. The customers’ names are made from two word lists and belong to nobody, the venues are invented, and the only cards it takes are Stripe’s test cards, which move no money. The delivery places are 64 public places in Salt Lake City from OpenStreetMap, such as parks, stations, gardens and libraries, shown by their map labels: a drop-off spot, never anybody’s home, and no street address anywhere.

Every visitor gets a private copy of the bakery, a sandbox, and every sandbox is deleted every night at 10:00 UTC. The privacy page says what is kept until then, which is nothing that names you.

Who built it, and why

It was built by the person behind ihaveasegway.com, whose lab shows five principles of distributed systems as simulations in your browser, each about a made-up bakery: queues, caches, backfills, consensus and vehicle routing. A simulation shows what its rules say and no more. This bakery is the same principles in production code, run for real on infrastructure that is paid for, with every backend in Rust on Cloudflare. How it’s built says which principle runs where, and the repository holds the code, the tests and every decision.