I applied online. The process took 3 weeks. I interviewed at AlphaSights (London, England) in Jun 2017
Interview
Initial video interview in which I recorded responses to displayed questions. I sent my CV to apply for the position and got an answer within one day. Then Alphasights gives you 7 days to record the video and write 3 motivational statements.
One think to bear in mind is that introductory video, in which they describe the process to you, does not give correct information (what a shame). In the video they say you'll be given 15 seconds to think about your response, and 30 to 120 seconds to respond. In reality, it's 30 seconds thinking time and 60 seconds talking time.
Although they say they'd contact you within two weeks, this time it took them three. I didn't receive an offer, no feedback was given.