After applying for my position I was contacted roughly 1 week later by the hiring manager to schedule an interview. I was interviewed by the supervisor to whom I would report, as well as one other manager within the department. The questions appeared to be pre-written, and there did not seem to be much organic follow up.
Within two business days I received a call asking to set up a second interview, with the supervisor and department director. That interview did repeat many of the same questions from the first interview, and seemed to follow the same outline. The director did tend to ask more "off script" questions.
Within another 3 business days I received an offer from the director.
All in all, it seemed to be a standard series of interviews - firstly the supervisor and close colleague vet you, then they bring preferred candidates to the director for final approval. I do believe that the timeline I experienced was unusually expedited due to the need to bring on this position in advance of a project launch.