I applied online after I heard about them during a presentation in university. They contacted me immediately and proceeded with an informal interview about my motivations and aspirations. They want you to have thoroughly researched them and they want to see that you know what you want. Then we proceeded with an algorithms interview which was consisting of only one averagely difficult algorithmic question. However the presentation of my solution and my line of thought were poor and I didn't continue on the next stage (which was an on-site interview in Seattle, US).