I initially met them at a career fair at my university. A week later, they interviewed me in person, on campus. I met with one of their engineers and he asked me one extended question. There were some aspects I didn't know about, but I told him that I didn't know, and he simply moved on to something I might know.

A few weeks later they invited me to their office for the final interviews, and there were a series of 4 or 5 technical interviews. The questions were pretty standard design/algorithms fair.

Design a news feed aggregator where the user has subscribed to a number of feeds but the total content of those feeds is much higher than the user actually wants to consume.