The signal varies and I think you need to calmly reflect on the data points which is hard. But I can imagine a few scenarios:
Let's say you recognize that you "underperform" versus your capability because you get insanely nervous. At some point you have to realize that your ability to grow depends on your ability to get your nerves under control. How you do that is the next question but that could be one observation.
You can seek patterns of what kind of interviews you tend to fail out on. Eg, is it coding, algorithmic, problem solving, behavioral, whatever. Once you have that zeroed in, you can ask yourself (and the internet): how can I get better at X type of interview.
More generally, you can seek for patterns of what kinds of questions surprised you and you had to make shit up on the spot, but could have been better prepped? EG if you go "hmm let's see" if you are asked about the coolest thing you've worked on or whatever, maybe that's the kind of topic you can pregame and have a story for.
Another maybe subtler thing is reading the interviewer. What are the things you were saying/doing where the interviewer was visibly happy/impressed vs confused, where did they say "that's great, go on" and where did they go "hmm.. but what about.." In the moment you may have just taken the "what about" as a prompt but in reality they may have seen you struggle and tried to help you - what can you do to prep for that type of questions next time?
I can go on - but the conclusion is something like this - I know a bunch of people who every interview they had, they think they nailed it and then they are totally shocked to not advance. And I know people who can reflect on what went poorly and adjust for next time. I don't know how to teach someone to recognize all the signals like this but it's definitely there to be perceived if one looks.
Let's say you recognize that you "underperform" versus your capability because you get insanely nervous. At some point you have to realize that your ability to grow depends on your ability to get your nerves under control. How you do that is the next question but that could be one observation.
You can seek patterns of what kind of interviews you tend to fail out on. Eg, is it coding, algorithmic, problem solving, behavioral, whatever. Once you have that zeroed in, you can ask yourself (and the internet): how can I get better at X type of interview.
More generally, you can seek for patterns of what kinds of questions surprised you and you had to make shit up on the spot, but could have been better prepped? EG if you go "hmm let's see" if you are asked about the coolest thing you've worked on or whatever, maybe that's the kind of topic you can pregame and have a story for.
Another maybe subtler thing is reading the interviewer. What are the things you were saying/doing where the interviewer was visibly happy/impressed vs confused, where did they say "that's great, go on" and where did they go "hmm.. but what about.." In the moment you may have just taken the "what about" as a prompt but in reality they may have seen you struggle and tried to help you - what can you do to prep for that type of questions next time?
I can go on - but the conclusion is something like this - I know a bunch of people who every interview they had, they think they nailed it and then they are totally shocked to not advance. And I know people who can reflect on what went poorly and adjust for next time. I don't know how to teach someone to recognize all the signals like this but it's definitely there to be perceived if one looks.