I meant Peter principle:

https://en.wikipedia.org/wiki/Peter_principle

So you meant to talk about "Peters principle", not "Peter principle"... I can't find anything on the first, that isn't really the second.

It really is applicable, whether you say "Peter/Peters".

The point is that if you're getting interviewed by someone who cannot understand your job, they are in the throes of a Peter principle manifestation, and you are very likely to end up in the same situation if you don't identify the incompetence - you'll inherit it.