I had a total of five interviews over the course of two months - the first was with the hiring manager, followed by a project/presentation, two interviews with higher-ups, and then an interview with HR. I heard back from HR 1-2 weeks after each interview with details on the next step, and in my final interview with HR they asked for references. I did not receive an offer but they let me know that the decision came down to myself and one other candidate.