Mathematica Research Assistant interview questions

Really nice interviewers, but a very long process. From the interviews, it seems like a very good place to work. However, they left me hanging for weeks in the end without telling me they had already decided on someone else.

1 interview with HR, 1 technical interview, 1 3-hour in-person interview. The technical interview was just walking through a code sample you submit. The in-person interview included 20/30 minute interviews with folks of various seniority.