One of my first interviews was at a place that made a job interviewing web app platform. After a programming exercise they decided to bring me in for an in-person interview. Long story short, I bombed with every person that I talked to over the course of the next 3-4 hours.
The first part was a system design interview. I had never done one of these, and my experience up to this point was basically working on small scale web apps at a local software development agency.
Next I continued on to an algorithm-focused white board exercise. It was something about trees, but again I was not able to articulate anything. I remember saying something like, "Recursion is bad", and immediately I could sense that that was a mistake. What I meant was that with Python you have to be mindful of recursion because you can get that "Maximum call stack size exceeded" error.
Next we ate lunch. I attempted to engage in conversation with an engineer by asking her where she had studied. She replied, and I then made the mistake of speaking negatively about the school that I knew was her school's competitor. Basically my attempt at comradery fell flat and I just looked like an idiot. The thing is that in reality I could care less about people's schools. I was just trying to be conversational, but failed.
After lunch, I had a meeting with a person who held a high-ranking position in the engineering department, possibly a director. His spacious office with a window indicated his significance. During the meeting, he inquired about my academic background and what I had learned in school. This particular part of the interview left me with the impression that I had failed to learn anything of value.
He had me work on some problem about a "Bipartite Graph" - Like prove that this graph is bipartite, or something like that. He had me do it on his window with expo markers, and it was taking me so long to get through this problem he actually left the room for a good 5 minutes and left me in there to mull it over.
The final part of the interview was with the front-end people. I don't remember much about this other than talking about React, since it was the hot new thing at that point.
By the end of the day, I knew I had done a bad job, and I felt very dumb. I remember emailing the guy shortly after leaving, basically apologizing for doing such a bad job, and that, "I promise I will do a good job if you choose to hire me".
I still cringe thinking about this experience, but it's also kind of funny that I could have this type of experience at a company who literally made an interviewing platform. I thought that was pretty ironic. I recognize that I did a pretty bad job, but nobody deserves to feel like I did after that interview.