Had a call with a manager with a tech background, followed by a final round 1 hour long interview. The call with the manager with a tech background went well. I was informed the final round would not be technical at all and would be with a non-technical manager. The interviewer was changed at the start of the interview and it was an hour of asking technical questions, many of which were not actually relevant to the potential project. This included the math behind some of the questions. However, the interviewer was someone with a public affairs and philosophy background, with no expertise in the algorithms I was describing. The feedback from the interview was that I did not understand these algorithms well enough. I believe I could have prepared more for the interview and answered the questions better, but I was misinformed and given a less than favorable assessment of my technical abilities by someone who did not understand them himself.