You just joined Marquee, which sells cinema tickets. Someone picks a movie and a time, picks a seat from the map, and pays. Here is the thing to get right: two people must never turn up holding a ticket for the same seat. If both tap “pay” for seat 12F at the same instant, one of them has to be told it has gone — and it is the database that has to stop it, not the app. Design the first simple database behind it.

out of scopePayment gateways · seat holds · refunds · loyalty points · food orders