Ticket Booking — Ticketmaster-class flash sales
500K users in 60 s · 50K seats · no seat sold twice · a waiting room converts an 8.3K/s stampede into a 250/s admitted trickle
arrows 0/20cards 12letters A–K
happy-pathside-effectfailure-compnew-infra (none)
▶ BOTE — canonical numbers (every N- chip in the rail links here)▶ Failure playbook (A–K)▶ What breaks first · contested choices · interview framing