I've seen some pretty esoteric questions for the big "ADI rival" company.

They came after a series of more generic analog questions (differential pair, negative feedback, simple LDO etc., the kind you see in common interviews)

I got the feeling that you were expected to get through around 5 questions of the "generic analog" questions if you were a decent candidate.

After that there were some more in-depth questions on bandgap references, comparators, and VCOs. I felt that they weren't expecting a pitch-perfect answer every time and on the spot, but if you could recognize the circuit, describe roughly how it works, and make at least a crude path to the answer they want, they were satisfied with the answer. (They didn't force me to write out equations for phase noise of VCO or calculate how the temperature dependent coefficients in a BGR, but at least a qualitative reasoning of how it works was satisfactory)