I was shocked and impressed to receive an initial email from the recruiter within 30 minutes of submitting my application online. I had a phone screening with the recruiter a few days later, and a phone call with the hiring manager the following week. A few weeks after that, I went into the Cambridge office for 3 hours of 1:1 interviews with the selection team. The final round - which I was not selected for - was to do a presentation on a TBD topic. The people were all extremely friendly and the interviews were very conversational. Not much in the way of redundant or duplicative questions. Company is very metrics & results-driven, so to the extent that you can provide concrete examples (including metrics) for the questions they ask, you will likely go farther in the selection process.