At Buffer, we’ve been using Kubernetes since 2016. We’ve been managing our k8s (kubernetes) cluster with kops, it has about 60 nodes (on AWS), and runs about 1500 containers. Our transition to a micro-service architecture has been full of trial and errors. Even after a few years running k8s, we are still learning its secrets. This post will talk about how something we thought was a good thing, but ended up to be not as great as we thought: CPU limits.