I felt that the team didn't know what they wanted.

After stating that experience and knowledge of "large scale systems" wasn't required, it became the deciding factor in the decision.

Technical interviews were fine, but often focused on one particular technical aspect. If you didn't have knowledge in that specific area, the interview didn't go well.

The process did allow for a re-take of an interview if it didn't provide a good signal the first time around.

I would have preferred a clearer understanding of what the company actually wanted.

Design of a system to distribute updates to billions of smartphones within a specified window.