This is a question I have a ton of experience with, and I can confidently say: occasionally! I've had interviews where they found out (either I advertised or it was out from jump) and they didn't even try to hide it. One town manager rolled his eyes after I advertised, turned his chair, and spent the rest of the interview on his phone. Another just talked to someone off (zoom) camera the whole time. Some times people put the pen cap back on the pen and stopped taking notes and pretended to carry on with the charade. Fuck all them. I don't want to work for you. Insert Michael Jordan meme here. However, most other times, I never had any idea as to why I wasn't hired. Maybe they knew they were going to promote from within or already knew who they were going to hire, but they had to go thru the motions by law. Sometimes I knew I "scored" probably a 95 on an interview, but maybe someone else "scored" a 99. I will never know. Maybe I was perfect for a job, but someone else was also perfect and someone knew someone who worked with them and so they had a recommendation. Again, I will never know. Maybe they interviewed 50 people and you got lost in the mix. Maybe it was complete discrimination. Maybe I didn't notice my tie looked weird and my hair was a bit of a mess. Maybe my internet was crappy that day and one of the interviewers was is a pissy mood. You will almost always never know why, so you can't take it personally. You either did the best you could, or you take it as a learning experience and you do better next time. Dwelling on the 'I must have fucked up and am totally to blame' does none of us any good.