Eleos Senior Full Stack Developer interview questions

The interview was on Zoom and felt very informal. The interviewer was sitting on his couch at home, occasionally shifting his laptop (which was apparently on his lap), and he spoke at length about himself, particularly about his military reserve service, something that didn’t interest me and didn’t seem relevant to the interview. Overall, most of the interview was fine, but then came a point where the interviewer asked me to talk about "the hardest problem I've ever solved during my years as a programmer." I presented a system I built a few years ago, and to put it mildly, he didn’t like it. At that moment, he stopped being nice and started speaking to me in a tone that was insulting and overly direct, which didn’t seem appropriate for an interview. He began talking about how "he knows what kind of programmer I am" and that he couldn’t understand why I showed him that system I built, claiming there were poor solutions I had implemented. I was very embarrassed at that moment. Then he started telling me that he believed I wouldn’t pass the backend test, which is the next step in the process. He said I had no understanding of trade-offs, even though we didn’t discuss that in the context of the system, and I didn’t understand how it was relevant to a system I designed years ago.