When I was in college, the #1 source for interview feedback for me was when my friends and I would get back from on-campus interviews and "compare notes". After

When I was in college, the #1 source for interview feedback for me was when my friends and I would get back from on-campus interviews and "compare notes". Afterwards we'd practice interviewing and being interviewed by and solving problems together. Getting a "reason" from a prospective employer isn't really helpful; it's usually not "oh if you knew what a skip list is then you would have gotten the job". It's more, "are you a better fit than the other candidates", and actually talking to them can help you gauge your strengths and weaknesses relative to them.