It was honestly super fun and challenging but also a complete waste of time for all of us. I ended up ballparking their technical questions and puzzles, yet at the end, I get told I didn't have enough experience. Why bother bringing me in if experience > skills? I knew I was not going to get the job walking in because I would be the youngest person there but I wanted to experience getting interviewed by wicked smart Caltech Physicist. The questions they asked were actually pretty tough and was a lot like playing chess. The technical questions where nowhere near as hard as a tech company. In fact, I even corrected my interviewer twice because he didn't take into consideration time-space complexity. Overall, it was a great experience for me personally because I got a free lunch and experience interviewing at a nontech company. I am sure I am just upset because it was a waste of time for most of us since I could tell they didn't expect a 23-year-old to be interviewed unless I was a genius.