The first interview was via email questions, then followed up by a second with a call from the same person (recruiter). Third round was talking to the person I'd be working with directly, and fourth was being interviewed in the office by the team I'd be working with. Finally I spoke with another manager in London over the phone who does approvals for the team. Multiple interviews in this fashion are not uncommon in Silicon Valley so it wasn't really a surprise. Overall I liked that they were interested in why I chose Splunk and why I was interested in this field personally, over emphasizing the checklist of the many requirements this job entailed. They also complimented my work more than other interviewers have in the past, which I really appreciated.