System Design Interview: Designing a Ticket Booking System (Ticketmaster-style)

The hard part isn't browsing events; it's selling a limited number of seats to a crowd that all clicks "buy" in the same second.

Requirements

• Browse events and see a seat map with availability.
• Hold seats for a few minutes during checkout; never sell the same seat twice.
• Survive "on-sale" spikes: 1M users arriving for 50k seats.