I had an initial hour long phone call that was a combination of explanation, introduction, and some more difficult behavioral/situational questions and technical questions on RCTs/econometrics. All of it was very cordial, though. After that there was supposed to be a stata test - I was not currently at a university nor did I have access to stata so I would have had to find a way to pay for it. At this point I had another job offer that I decided to take and backed out before the stata test. Overall, it moved very, very slowly (to be expected with academics).