This is the real app, not a video. Order from the phone (Table 1 at Salt & Sinangag, a made-up 24-hour silog place in Malolos) and watch the ticket land on the kitchen screen. Bump it through the line and the phone follows along.
Phones, the kitchen and the floor share one connection per restaurant through a Cloudflare Durable Object. A ticket fired from a table reaches the kitchen in well under a second, with no polling.
While a staff screen is open, simulated tables sit down, order, eat, ask for the bill and pay, so there's always something on the line. Switch it off to see only your own orders.
Each visitor gets a private restaurant with its own menu, tables and sales. Change prices, mark dishes sold out, close tables. Nobody else sees it, and it's deleted after a week without visits.