The first call was with an HR representative who had no technical knowledge. I was given a 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 that lasted 2 hours with two different interviewers.

The first interview involved a programming challenge with the usual algorithmic trivia. You were required to use Swift and could not use any other programming language. The interviewer appeared disengaged and merely checked if your solution was correct and if you answered algorithmic complexity questions correctly. He specifically nitpicked typos and syntax errors in my code.

The second interview was for domain knowledge (iOS), and the interviewer asked 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 the interviewers were looking for experienced coders with extensive iOS domain know-how.

In an integer array, find a pair of numbers which add up to a given number.

In an integer array, find three numbers which add up to a given number.

Explain what an optional is in Swift.