Top iOS Interview Questions [2023]
iOS developers build applications for mobile devices powered by the iOS operating system. They build, test, and refine mobile applications for Apple iOS. Interviewing iOS candidates commonly consists of basic and advanced questions to assess technical ability. We sourced these questions from the iOS community based on developers’ own interview experience and what our clients found important to ask. Could you use help hiring iOS developers? Scalable Path’s experienced Talent Acquisition team can help.
iOS Interview Questions and Answers
These are the types of questions typically asked during iOS interviews. We created them to help you test your understanding of the popular programming language, or guide your initial technical screening with iOS candidates.
Can you explain closures to a new Swift developer?View Answer
What is the difference between App ID and Bundle ID?View Answer
How does the Apple Developer Program membership use certificates?View Answer
What is your experience with Accessibility tools on iOS?View Answer
Can you explain Mac Catalyst and its functionality?View Answer
Can you describe the four layers of the iOS architecture and the role of each layer?View Answer
Can you list the possible states in which an iOS application can be and the states to which the app can transition?View Answer
What is ARC in the Swift programming language, what is it for, and how does it work?View Answer
What is a lazy variable, and how does it work?View Answer
What does KVO mean, and what considerations must be taken in Swift to achieve it?View Answer
What is a phantom type in Swift, and what is it for?View Answer
What is Display P3, and what considerations should be taken when developing for wide gamut displays?View Answer
What does deep linking mean on iOS, and what are the options to implement deep links? What are the differences between these options?View Answer
What is the difference between self and Self in Swift, and what are the main uses of both?View Answer
What is a variadic function, and how do you implement one in Swift? How would you make a variadic function that accepts multiple types?View Answer
What is the difference between argument labels and parameter names in function parameters? Can you write a function without an argument label or name?View Answer
How would you use the targetEnvironment() compilation condition in Swift, and what is a common use case for it? Please provide a code snippet of a conditional compilation block using targetEnvironment(), with comments indicating what each block does.View Answer
Can you describe the process for configuring in-app purchases in an iOS app? View Answer
What are RealityKit and ARKit, and how do they differ from each other?View Answer
This list isn't exhaustive, and interviewing typically includes an assessment of soft skills and technical ability through a take-home assignment or live coding exercise. You can learn more about hiring here.
