The project manager approached me in Linkedin. When the project manager said they handle billions and even trillion of transactions that got my attention. I had one phone conversation with the manager, one hour skype interview and 4 hours on site interviews with 5 people. The interviewers were nice not intimidating hence helped me think clearly. When I got stuck in the interview, I could ask for some hint to the interviewers for some directions.

Interview process started with a recruiter getting in touch, understanding my skills, experience and fit for the position etc, then setting up a technical phone screen within the next couple weeks. Phone screen had a friendly interviewer who asked a couple of interesting algorithmic/coding problems, nothing too hard but not straightforward either (first one is simple, the next one builds on it etc). He encouraged me further down the correct path to reach the optimal solution. We then set up an on site interview in L.A. for a couple weeks later. The onsite was organized well, 'Bet' added a nice personal touch by writing a "Welcome xyz !" message on the whiteboard which was sweet ! I met with 5 people in all, including the co-founder & CIO (since this was for a small core team) who gave details about the company, culture, technical aspects of the job, etc & also asked more general & system design related questions. The first meeting with the CIO was followed by an engineer with further algorithmic/coding problems on whiteboard and a quick lunch, followed by the technical co-founder with system design questions, then another engineer with a coding problem (to be solved directly on his laptop) followed by a brief session with the HR. A total time of around 4 hours onsite & a pleasant experience with friendly, cool & talented folks.