The first call was with an HR with no technical knowledge. I was given multiple choice questionnaire with a set of tricky domain-specific questions, which I had to solve during the video call. The second stage was a video conference which lasted 2 hours with two different interviewers. The first interview was a programming challenge with the usual algorithmic trivia. You are required to use Swift and can't use any other programming language. The interviewer appeared to be disengaged from the process and merely checked if your solution is correct and that you answered correctly algorithmic complexity questions. He specifically nitpicked typos in my code, as well as syntax errors. The second interview was for domain knowledge (iOS), and the interviewer asked me in-depth questions about iOS frameworks, Swift and Objective-C. At the end of the interview, I was given a live coding challenge to implement a timer in Swift. Overall it appears that the interviewers were looking for experienced coders with a lot of iOS domain know-how.