Zero-Growth Stack, Real Gains: 10% CPU savings on the broadcast tier

Why stacks matter

PUCK GOLD’s broadcast tier handles millions of goroutines during peak overtime. Stacks grow with workload — and never shrink between game states. That left ~10% of CPU on the table.

The fix

We introduced a stack-allocation hint and a periodic shrink pass tied to game-state boundaries. Result: 10.4% CPU reduction across the fleet, no regression on tail latency.