Started with a offline exercise with a job related task (creating a DNS probing utility) with a small set of requirement. Was given a week to complete the task but could be done in 1-2 nights of work. After that, 4 technical interviews with different instant tasks and general conversation.

I was first contacted by a recruiter on linkedin. First round was 5 generic questions about my background, then a relatively easy programming challenge in C++. After that I had a first "informal chat" with the CTO about ThousandEyes, my background and my knowledge in networking protocols. Then I had 3 coding interviews in a row on Skype. It took a bit more than two hours. The people I interviewed with were all really helpful and enthusiastic, they sounded genuinely passionate about their work. After that I gave two references and I had an offer in the next week. I declined the offer but only because I want to do a PhD.