During load testing, room ticks began overrunning their 50 ms budget as simulated clients reached target density. Normal ticks took 10–20 ms; spikes took 100–300 ms, leaving clients two to six ticks behind. We had built the room service for a QQ-licensed casual pet game. It was designed for tens of millions of users; actual peak concurrency reached roughly 200,000 players.
I led the architecture selection and ECS implementation. Profiling showed how much CPU time component lookups consumed.