Nobody can judge their own interview performance - engineer or not. The hard part is that you as an interviewee don't really know what the interviewer is lookin

Nobody can judge their own interview performance - engineer or not. The hard part is that you as an interviewee don't really know what the interviewer is looking for. You may have nailed the back half of the interview, but you don't have the one skill they're looking for. Or sometimes you don't blow it at all and they love you, but there's one other person they interviewed for the position that blew them away. Trying to guess how well you did in an interview is folly. Hell, one interview tactic I use with people is to push them until they break: I keep asking technical questions until I reach a point where you say "I don't know". This sometimes makes people think they "failed" the interview, when all I'm really trying to do is see how much you know while also seeing how much you'll bullshit me on topics you don't know as well. Nobody can be an expert on everything, and interviews are as much about behavioral profiling as they are subject matter expertise.