I was contacted by an HR recruiter who found me on linked in. Was very nice and persistent about coming in for an informal chat to check the office, not for an interview. I accepted, was impressed by the technologies, the talent and the opportunities, then scheduled an interview a few days later. Two days after the interviews I was told the feedback was positive and started negotiating the offer.
Interviews were very technical, met with 4 engineers (about 3hrs), algorithms, big-o, lots of white-board coding and system design, though nothing super crazy. Very informal and casual, very relaxed environment, I wore nice jeans and nice shirt, which made me feel more comfortable, as the interviewing engineers were also very relaxed.