Three rounds of interviews, two in person and one on the phone. They were mostly very nice. However their questions were not very easy to handle. Didn't hear back from them since the second onsite interview (it's been more than 2 months).
Interview questions [1]
Question 1
Mostly technical and resume based questions. Since this role is about model implementation (so I guess), C++ skills were very much emphasized. A lot tests on that, including writing codes on an editor. Detail-driven. They were very interested in digging into your projects and asked many follow-up questions.