I had a series of technical interviews then coding challenges (Developing an app, coding some features on an existing codebase, etc). The interviews were via Phone and Google Hangouts. The app was an Android app and the feature coding was on both iOS and Android. I was flown out to San Francisco, to meet the people at the company and do some additional interviews for a day. Overall the experience was very good, and the recruiter who was working with me was very helpful in the entire process.