First, there was a phone screening with basic questions about who I was, what I was interested in and an opportunity for me to ask questions. Following that, there was an on-site at their Cambridge offices where I had 4 interviews starting with two software engineers, their HR point person, another software engineer, and finally the CTO. On my way out they introduced me to the CEO. I was on a time crunch in terms of when I needed their offer by so they adjusted and gave me a response within 3 days.