Code is Cheap, Data is Forever: Why Your Schema Needs an Architect, Not a Coder

It’s 2:00 AM. Your phone buzzes on the nightstand. It’s PagerDuty. The production database is locked up. CPU is pegged at 100%. The "simple" query that worked perfectly with 1,000 users is now taking 30 seconds to run with 100,000 users. You’re looki...