I got contacted by the manger to do a semi-formal small interview on Microsoft teams asking some questions with a few simple technical questions. I then was called to do a phone interview (but I already did one recently for the company for a different position so they just carried over the same notes). Then I did the 1 hr technical interview. This had a CMOS logic gate question (What is the logic expression of this given schematic), a simple list off ideal op amp properties question, a few RC circuit questions, and a few analog to digital questions. I managed to get most expect a specific question which needed to know what the Fourier transform of a square wave input looked like in order to prove why the steady state output of the capacitor had some noise. I did not make it to the next round but it would be a in person interview where you do a short presentation on a topic. It also seems like judging from their response email that they thought I did good but I wasn't strong enough when it came to the follow up questions that were "indented to stretch beyond the initial concepts". If I had to give advice and guess what they are looking for, I would say they want to see someone who can give very in depth and detailed answers. Or not. Making they are just interviewing to get data with no intent of hiring like every other company as they have had this job posting up for months now.