Multiple rounds, four in total. First three were over the phone and the last was in person with several people. Really appreciated how fast they were in communicating every step. Make sure you really know about the company and do your research.

Applied online, received an email that same day scheduling a phone interview for a week later. A second phone interview was then scheduled a few days later, followed by a case-study which they gave you 24 hours to complete and finally a 5 person in-house interview. Overall, the interviews were not exceptionally difficult if you prepared and most of the people I spoke with were very friendly. They also spoke to me in Spanish during one of the interviews, I guess because they were considering me for the Latin American group.