It was a while ago, but I believe it was 5 rounds of interviews. 4 via phone/video conference and the final in-person in NYC. I was traveling in from out-of-state for the interview - they knew, and had zero consideration for it. Not a huge deal, but a big contrast from the other organizations I was interviewing with at the time. Everybody I interviewed was friendly and knowledgeable. I thought the in-person interview rounds went well, but never heard from them again after leaving the office. Not being the right fit wasn't a big deal, but I thought it was kind of rude and unprofessional to ghost somebody after 5 rounds of interviews.