However, it seemed I was being "punished" for some bad past experience they had, or they were uncharacteristically unreasonable, condescending and rude, no doubt taking "revenge" over some past unlucky investment on a not-so-worthy employee. Cannot be explained otherwise.
It was the only interview where I felt uncomfortable with a feeling almost like the interviewers "were out to get me", rather than find common ground and see if we are a good fit.
Because when you interview an experienced professional, it's more about the fit with the company culture and the personalities of the hiring managers and the team, and less about testing their knowledge and certainly much less about denigrating their experience, skills and qualifications.
My good manners prevented me from responding with a f*ck off in several points during the interview. They wanted to know why my PhD took 5 instead of 4 years, as if they haven't lived in the real world where people actually hold full-time jobs in parallel with completing a demanding PhD. They wanted to know how I would define X, even though X has nothing to do with the tech I would use on the job (and they admitted that when I asked). They were sarcastic about the patent I was involved in co-inventing, quickly dismissing it as of no importance. It was as if their goal was to actually shoot down my CV rather than understand where I am coming from.
It was good luck that they behaved this way so early on, because when I left that room, there was absolutely no doubt in my mind that I would be miserable working with them.
I just wish people were a bit smarter, and minded their manners, especially when we're talking about people in the positions of CEO and Head of Engineering. Because it's smart to leave the room with a good impression about you as you represent your company and your company's overall culture. It is smart to be well-mannered and considerate to the person in front of you. Because even when an experienced professional does not get to work for you, they will still have formed an opinion about you and the company you represent as a result of this encounter.
You see, an interview is not only for the interviewer, but also for the interviewee to judge the opposite party.