iOS interview questions for FAANG+ companies.

Faiz ulla Sharief
2 min readMay 2, 2021


If you are an advanced iOS developer and looking forward to get into Big product based companies, You are at the right place. Well, even if you’re a beginner, do not worry, as you are going to get some knowledge that 80% of the beginners do not know :)

Well we all have always had a dream to get into FAANG+ companies, and I did too. I have given many, yes many interviews at top Indian product based companies and noted a pattern in the questions that they ask as opposed to early startups and service based companies. Hold on tight!! and assemble focus, as I walk you through some of the questions/topics that are most commonly asked by these companies.

Please note that I might not be able to write answers to all of them as it will make this post a never ending one and I will have to include a TLDR which, end of the day will not provide any value 😆. And in case you if you feel I should answer the questions, lemme know in the comments :)

  1. Can delegation be implemented without a protocol? If yes, then why do we need a Protocol?
  2. When to use and when not to use, the Singleton pattern?
  3. Why are IBOutlets weak by default? What happens when we make them strong? Is it even a problem?
  4. What are the possible ways to draw a circle on the UI without using a UIBezierPath?
  5. Why do we have design patterns like MVC, MVVM, VIPER etc.? What’s their significance?
  6. How do cocoapods work?
  7. What’s the difference between static and class keywords in Swift?
  8. What is the essence of higher order functions? Why are they special? Why are they called so?
  9. What is nil in Swift? How is it different from Null in other languages?
  10. Your App UI is frozen. Which tool from Instruments will you use to debug this scenario?
  11. How do you keep the memory usage and CPU usage minimal and also achieve smooth scrolling, in an infinite image scrolling scenario like Instagram? (Design Question)
  12. What is Objective C++?
  13. Why did Apple chose to go with structures to implement primitive types in Swift?
  14. What is frozen struct in Swift?
  15. What are ‘@dynamicCallable’ and ‘dynamic member lookup’ in Swift?

Kudos!! You’ve reached the end.

If you’ve made it so far and you know/found out answers to the above questions, Congratulations 🎊 you’re now a step ahead on your journey. And in case any of these questions are bothering you at night 😵‍💫🤯, feel free to get in touch :)

If you liked my post, do support👏🏻. Until next one, C’ya and happy learning.



Faiz ulla Sharief

iOS Dev | Industry Leader | Public Speaker | Tech Enthusiast.