Autoscaling doesn't save you at 30,000 requests per second — your dependencies do

There's a comfortable story about peak traffic: load goes up, the autoscaler notices, pods multiply, everyone keeps their evening. I've watched that story hold, and I've watched it fail in a specific and instructive way — the autoscaler worked perfectly and the platform degraded anyway. Running transaction paths at sustained peaks in the tens of thousands of requests per second teaches you that horizontal scaling is the easy half of the problem. The hard half is that everything your new pods talk to did not scale, and now there are more of them asking. Scale-up triggers.