Once I was interviewing for a senior software engineer position for a big financial company. Before the start of the in-person interview process they had each candidate solve a Java programming question regarding encryption/decryption (according to their HR only 30% passes the initial filter and my solution was one of the best with regards to design, time to finish (I only spent 1hr to finish the exercise), runtime efficiency, and test coverage). They gave us each a laptop and 3 hours to solve the question. I got really good feedback after the exercise and was asked to go through the remaining gauntlet of more Java interview questions (2 more interview sessions w/ different people (tech lead and vp) to be exact).
At the last interview with one of the executive director, he dropped me a math puzzle question that is not related to the job at all, suffice to say I bombed the last interview. This was really frustrating and is a complete waste of time on my end since their office is a bit far from where I currently work.