You're actually lucky that you even got a rejection. I have a friend who has interviewed at quite a few companies that are talked about in high regard by people

You're actually lucky that you even got a rejection. I have a friend who has interviewed at quite a few companies that are talked about in high regard by people in the tech industry and after his interview, he hasn't heard back at all. I know him he is skilled and certainly worthy of serious consideration....so it has been surprising seeing how many have rejected him after an interview without a courtesy email. You either weren't good enough or weren't a good fit. I've had situations where I interviewed at jobs where I'm asked "What type of work will make you love coming to work and also what is your ultimate career goal". If your answer isn't exactly what they are looking for, you might not be "as good of a fit as they want". This is actually a good thing because they are saving you a lot of time by getting you to work on something you like, rather than something might not know you don't like. With that said, I expect that the tech hiring process will be unrecognizable a few years from now.