This was a third stage of the interview process. The first two included a screening with a recruiter and a live coding challenge over the phone with an iOS team member. The on-site interview was about 1 hour long and included two white-board exercises and a technical problem that you walked the interviewer through.

First interview was a 20-30 minute phone call with the recruiter. If that goes well, second interview is typically a HackerRank test that you take online with a 90 min. time limit. If you "pass" the online test, next step is typically an on-site interview.