I had an phone screen that lasted 45 mins or so. The hiring manager asked some technical questions. It was followed by two on-site interviews - the first one was a 2 hour interview with 2 people after which I was called in for a longer 4 hour onsite interview. All the interviews, except the one with CTO, were not too difficult and the interviewers were nice. The CEO asked some good questions - but he intentionally made them tricky with his bad communication.