>too many servers... My best advise about scaling, I once read (might have been right here on HN) is many devs know their primary bottleneck. Be it the "master

>too many servers... My best advise about scaling, I once read (might have been right here on HN) is many devs know their primary bottleneck. Be it the "master-db", 3rd-party-api, login-service etc. But few devs knows the "2nd slowest/bottleneck" in their service stack. Not saying this was the case here, but always good to think (at least has a mental exercise) about what comes after your primary-bottleneck. If it's a long standing bottleneck, one day it gets fixed (sw update, better arch) and suddenly everything goes down since now you hitting a new bottleneck you never even thought about scaling.