Senior iOS Engineer Interview Questions and Answers

Sample Interview Questions

• Can you walk us through your favorite iOS project and why it stands out to you?

  Purpose: To gauge the candidate's passion and experience with iOS projects.

  Sample answer

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  Sure! My favorite project was a fitness app that used CoreMotion to track user activity. It stands out because it challenged me to integrate various iOS frameworks seamlessly.

• ️ How do you handle memory management in Swift?

  Purpose: To assess the candidate's understanding of memory management in Swift.

  Sample answer

  “

  I use Automatic Reference Counting (ARC) to manage memory. I also make sure to avoid retain cycles by using weak and unowned references where appropriate.

• What's the most challenging bug you've encountered in an iOS app, and how did you squash it? 🪲

  Purpose: To understand the candidate's problem-solving skills and debugging process.

  Sample answer

  “

  I once faced a tricky bug related to background app refresh. I used Xcode's debugging tools and logs to trace the issue and found that a background task was not being properly terminated.

• How do you ensure your app provides a smooth user experience?

  Purpose: To evaluate the candidate's focus on user experience and performance optimization.

  Sample answer

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  I prioritize efficient code, use Instruments to profile performance, and ensure smooth animations and transitions. I also gather user feedback to continuously improve the app.

• How do you handle version control in your projects? ️

  Purpose: To assess the candidate's familiarity with version control systems.

  Sample answer

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  I use Git for version control, following a branching strategy like GitFlow. This helps in managing features, bug fixes, and releases efficiently.

• Can you explain the difference between a delegate and a closure in Swift?

  Purpose: To test the candidate's understanding of common Swift concepts.

  Sample answer

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  A delegate is a design pattern that allows one object to communicate with another, while a closure is a self-contained block of functionality that can be passed around and used in your code.

• How do you handle networking in your iOS apps?

  Purpose: To evaluate the candidate's approach to networking and API integration.

  Sample answer

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  I use URLSession for networking tasks and often leverage libraries like Alamofire for more complex needs. I also ensure proper error handling and data parsing.

• How do you approach testing in your iOS projects?

  Purpose: To understand the candidate's testing strategies and practices.

  Sample answer

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  I write unit tests using XCTest and also implement UI tests. I believe in Test-Driven Development (TDD) to ensure code quality and reliability.

• How do you handle UI/UX design in your apps? ️

  Purpose: To assess the candidate's approach to UI/UX design and collaboration with designers.

  Sample answer

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  I collaborate closely with designers, using tools like Sketch and Zeplin. I also follow Apple's Human Interface Guidelines to ensure a consistent and intuitive user experience.

• How do you stay updated with the latest iOS development trends and technologies?

  Purpose: To gauge the candidate's commitment to continuous learning and staying current.

  Sample answer

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  I regularly follow WWDC sessions, read blogs, and participate in iOS developer communities. I also experiment with new frameworks and tools in side projects.