First stage was ten minute chat with recruiter who seemed to really know the business. Second stage was in depth interview/interrogation with cfo and recruiter, this lasted two hours, but really tested answers given. Next stage was a bit more relaxed with md and cfo again, offered position, most difficult refusal ever as these guys did seem to put real effort into finding someone and knew what they were looking for which seems to be rare these days. Unfortunately alternative offer came in.