I had a first round interview that's mostly fit with a short case. I was then invited for the final round in their office in Newton, MA, for a lunch presentation and four back-to-back 45 min interviews. The interviews were nearly identical-- they all asked for market sizing a new drug for a certain condition. I did the case posted on their website beforehand and basically learned the structure they were looking for to get at the market size. Some interviews asked about how a drug mechanism could possibly work, to test for scientific understanding/thinking.
The analysts I interviewed with were all pleasant and interesting, and I could see them being good colleagues. That said, a couple of my interviewers took to their computers and answered emails while I was working on the case. One even told me to do the math and let them know once I was done. It seemed like it's because they were truly busy, not rude, but it was still unprofessional.
I did not get an offer, but was notified of this decision over the phone. In other words, one of the analysts emailed me to schedule a call. Then, once we connected on the phone, she notified me that I was not selected and gave me feedback. Although I appreciated that they provide feedback, I thought it was strange/awkward to call to give the bad news. An email would have been better. I also didn't think the feedback to be applicable to my interviews, but rather generic.