They flew me out to Utah, and I had a half day of interviews with 7 or 8 people in a row. Several weeks later they called and apologized for not giving me an answer yet - everyone had liked me. I was told they were just waiting on final approvals and they would provide an update in two weeks, even if it was that they had no update. They asked me to keep them informed on how my search was going. A month later I asked if there was any news. They never replied. Ghosted.
The difficulty was just the volume of interviews one after the other, not the questions themselves.