[coldtea]

>Like autoscale horizontally and/or vertically, sharding or just writing better code?

Sometimes you just have a server, not some elastic horizontal setup, or a budget for vertical scaling.

And "writing better code" is an optimization thing, not a general way to handle back-pressure (you can have back-pressure in a fully optimized program too, and even for non-optimal code you don't want to just have to iterate and refactor/improve the code every time there's back-pressure).