I had an HR interview and then 4 hour-long technical interviews. All the interviewers asked reasonable questions that seemed relevant except for one. He showed up with a recursive gotcha question, the application of which I have never seen in any of the roles I have been in. It was also something for which there are abundant performant libraries out there. That particular interviewer looked bored the whole time. So everything seemed good and then it ended up a no-go. Weird experience overall.