Initial HR vetting call followed by a telephone interview with technical architect. Then had an onsite interview with four meetings. First three/four rounds were technical/white boarding and the last was with their senior director. First round had two design questions to whiteboard and brainstorm with the architect. Second round was another white boarding round with another senior adviser. In the third round, had a more traditional technical interview. In the middle they called another senior developer in to the interview and he asked a few other white boarding questions. The last half hour was just talking to the senior director about the team, type of work and so forth