I run training courses on how to leave a positive impression on a candidate. I always open by asking people to tell me about their worst experience in an interview. Then I share mine, and it was with the then CEO of PageUp in Singapore in about 2015. It was basically a psychometric test that went on for 3 hrs. I came during my lunch break. I was not told it would take so long. A robot could have done a better job as an interviewer. I left the interview knowing that I would not get the job but also that there's no way I'd work for this person.
I always finish my story about the consequences of leaving a bad impression. In my current position, PageUp approached me to sell their service to me. My first instinct was to invite them over to my office and hold them for 3 hours before declining, but I'm nicer than that. I simply said no thank you while in my head I thought, never in a million years.