The process was two screening calls one with an internal recruiter and the second with a technical manager, once passed the two calls it was then a on-site 4 x 45 minute one on one interview sessions with a mix of people and technical questioning. All interviewers were very able for the process except for one engineer who seemed to be fairly uncomfortable in the room, he either was not prepared or was a last minute replacement.
Overall I found that the interviews were very relaxed and friendly with plenty of detail on the role and company. It does look and sound like an interesting place to work.