Very long, repeat interviews with the same person. Last round with presentation followed by 6 one on ones. They could have informed much before the final round if you aren't in consideration.

First, a 30 minute conversation with the hiring manger about my experiences and interests. Second, a 4.5 hour interview. The first hour was a presentation + Q&A. The remaining 3.5 hours were a series of 2-on-1 interviews with the audience members of the presentation.