Why Cloud-First Event Check-ins Fail at 10k Scale And How We Built an Edge-First Alternative
If you have ever built an event registration or ticketing app, the default architecture usually looks clean on paper: Attendee shows a QR code on their phone. A scanner app hits a cloud REST API (POST /api/v1/checkin). An auth token is verified, PostgreSQL flips checked_in = true, and a 200 OK returns. Total round-trip time: ~180ms. In staging, this works flawlessly. Even with synthetic loads of 500 req/sec across a few load balancers, everything stays green. Then production happens at an enter…