I'm young and have also been turned down often due to whiteboard interviews. What surprises me is that you were only rejected twice in a few months. I had to go

I'm young and have also been turned down often due to whiteboard interviews. What surprises me is that you were only rejected twice in a few months. I had to go through many, many more rejections than that much quicker than that before I found a good fit. Don't assume these interviews favor young people, it certainly didn't feel like that to me. I think most places just want to reject most people, because it's easier to justify rejecting someone good than accepting someone bad.