Meta Senior Software Developer interview questions

The interview was 5-6 hours of whiteboard problems. The pace of the interview was very quick, with barely enough time to simply write the solutions to the problems. Almost the entire time was spent standing at the whiteboard. At least one of the problems was quite long. The interviewer was late and cutting into the next round. He spent the time I was solving the problem typing into chat on his laptop. I left the interview expecting a good chance of an offer as I had solved most of the problems except for running out of time in that case. As a senior candidate, I don't feel the expected value of the return on preparation and time to do the interview was worth it, given the probability of no-hire for what seems to have been minor concerns.