August 19, 2026 · 4 min read
The Scale Tax: what auto-scaling doesn't tell you about your next invoice
Scaling an app is the fun problem. Paying for it after the traffic leaves is the one nobody schedules a meeting for. A field record of how we built a code-execution engine that scales to 500+ concurrent users — and the auto-scaling traps that nearly kept it billing us long after the users went home.