I’ve worked in several python shops, and now work with Rust. Python’s performance can be a real cost problem at scale. Where this bit us in the past was with the sheer number of containers and nodes we had to spin up in k8s to support comparatively moderate traffic in a relatively simple web application.

It’s been a while, so take the numbers with a grain of salt, but where we might have needed 10 pods across several nodes to process a measly 100 req/s, we can easily handle that with a single pod running a web application written in rust, with plenty of room to spare. I suspect some of it is due to the GIL: you need to scale instances rather than threads to get more performance in Python.

Anyway, at some point the cost of all those extra nodes adds up, or your database can’t handle the absurd number of concurrent connections all your pods are establishing, or whatever.