I'm happy to provide feedback for anyone reading this - Mock interviews or code challenge reviews. No guarantee it's helpful but I'm not a black hole at least!

Yeah companies generally won't provide feedback, there is no benefit to them and many times candidates will just argue about it anyways.

For better feedback there are some good mock interview companies out there, or you can ask a friend or mentor. I've also had really good luck just talking to Gemini/Chat GPT.

Not a huge AI guy but this is something LLMs can do quite well (less so before gpt-5 because that model was a sycophant) but I learned a lot about personality interviews by simply having the AI throw questions at me and then taking my answers apart.

I'm getting pretty old and have done a ton of interviews at this point in life.

There's never been a single one that went poorly and I didn't know exactly why without a word of feedback from the company I was interviewing with.

I disagree. I know when I get questions right, or can't do them. In my experience, either I screwed up a question and legit didn't get the job, or I was fine and the interview process is just a bit random. Sometimes it's the interviewer's fault for asking bad questions. Most commonly it's: "how do you light a fire?" "with a match" "but you don't have any matches" "a lighter" "no lighter either" "flint" "no flint" "stick and bow" "all the wood around you is wet" "I give up" "you use a magnifying glass of course!"

You can actually ask for feedback and usually they'll give it. In the EU they have to tell you what they wrote about you in their internal system under GDPR (or at least my company's lawyers believed that)!

The one time I got really great feedback unprompted from a hiring guy it was basically "they were disappointed you didn't know X" and I was like "weird, I do know X!". Very interesting to see it from the other side but I don't think it was very actionable.

Self reflection amend critique are skills too.