The word "judging" has multiple variant meanings. It is being used to mean two different things in this subthread.

Judging whether a candidate is coachable, their thought processes relevant to the job, understands the ideas etc is what the interview is for, you're right.

But "I'm not judging" doesn't refer to that. It refers instead to the concept in the word "judgemental". Some definitions of that are "having or displaying an overly critical point of view" and "thinking, speaking, or behaving in a manner that reflects a critical and condemnatory point of view".

Apologies are due, sir. Two things happened. First, I hastily read through the question and rushed my response. Second, just a few minutes prior I finished a workout and was quite exasperated.

The use of the term "not judging" is a bit strange, without further context.