The Peter Principle

How to use it. When designing career paths, separate "good at the job" from "good at managing people doing the job". A great engineer is not automatically a great engineering manager. Make the parallel track real, so it never feels like a consolation prize.

How it gets misused. Used to mock a specific person. The principle is about the promotion system. The person at the wrong level is a symptom of an organisation that promoted them there.