7 real iOS interview questions asked at Apple. Upvoted by engineers who cleared the loop. Covers Technical, System Design rounds.
Apple
Medium
Technical round
SwiftiOS
Explain how ARC (Automatic Reference Counting) works in Swift/Objective-C.
What is a retain cycle and how do you break one? Give an example using a delegate pattern and explain when to use weak vs unowned references.
↑ 91 upvotes · 34 engineers asked this · SDE1
Apple
Hard
System Design round
Distributed SystemsiOS
Design Apple Pay's tap-to-pay system. When a user taps their iPhone, a payment must complete in under 500ms even with no internet connection. Cover: secure element, tokenisation, NFC protocol, and offline authorisation.
↑ 59 upvotes · 38 engineers asked this · SDE2
Apple
Hard
Technical round
SwiftiOSKotlin
Explain iOS memory management: ARC, strong/weak/unowned references, retain cycles. How does the system handle memory pressure? Walk through what happens when an app receives a memory warning and is then terminated.
↑ 62 upvotes · 39 engineers asked this · SDE2
Apple
Hard
System Design round
Distributed SystemsiOS
Design Siri's speech recognition pipeline. Audio is captured on-device, processed, and a response is returned. How do you split on-device vs server processing to balance latency, privacy, and accuracy?
↑ 53 upvotes · 32 engineers asked this · SDE2
Apple
Medium
Technical round
SwiftiOS
How does Core Data work in iOS? Explain the managed object context, persistent store coordinator, and the fetch request pipeline. When would you use Core Data vs Realm vs SQLite directly?
↑ 43 upvotes · 26 engineers asked this · SDE2
Apple
Hard
Technical round
3-7 yearsPerformanceiOS
An iOS app's scroll performance drops to visibly janky frame rates on a list with complex cells. Walk through your process for diagnosing whether the bottleneck is layout, rendering, or data processing.
↑ 29 upvotes · 10 engineers asked this · Senior SDE
Apple
Medium
Technical round
2-6 yearsSecurityiOS
How would you design a feature that needs user location data for a core function, while minimizing what leaves the device and remains fully functional if the user denies location permission?
↑ 21 upvotes · 8 engineers asked this · Senior SDE
Explain how ARC (Automatic Reference Counting) works in Swift/Objective-C.
Explain how ARC (Automatic Reference Counting) works in Swift/Objective-C.
What is a retain cycle and how do you break one? Give an example using a delegate pattern and explain when to use weak vs unowned references.
Design Apple Pay's tap-to-pay system. When a user taps their iPhone, a payment must complete in under 500ms even with no internet connection. Cover: secure element, tokenisation, NFC protocol, and offline authorisation.
Design Apple Pay's tap-to-pay system. When a user taps their iPhone, a payment must complete in under 500ms even with no internet connection. Cover: secure element, tokenisation, NFC protocol, and offline authorisation.
Explain iOS memory management: ARC, strong/weak/unowned references, retain cycles. How does the system handle memory pressure? Walk through what happens when an app receives a memory warning and is then terminated.
Explain iOS memory management: ARC, strong/weak/unowned references, retain cycles. How does the system handle memory pressure? Walk through what happens when an app receives a memory warning and is then terminated.
Design Siri's speech recognition pipeline. Audio is captured on-device, processed, and a response is returned. How do you split on-device vs server processing to balance latency, privacy, and accuracy?
Design Siri's speech recognition pipeline. Audio is captured on-device, processed, and a response is returned. How do you split on-device vs server processing to balance latency, privacy, and accuracy?
How does Core Data work in iOS? Explain the managed object context, persistent store coordinator, and the fetch request pipeline. When would you use Core Data vs Realm vs SQLite directly?
How does Core Data work in iOS? Explain the managed object context, persistent store coordinator, and the fetch request pipeline. When would you use Core Data vs Realm vs SQLite directly?
An iOS app's scroll performance drops to visibly janky frame rates on a list with complex cells. Walk through your process for diagnosing whether the bottleneck is layout, rendering, or data processing.
An iOS app's scroll performance drops to visibly janky frame rates on a list with complex cells. Walk through your process for diagnosing whether the bottleneck is layout, rendering, or data processing.
How would you design a feature that needs user location data for a core function, while minimizing what leaves the device and remains fully functional if the user denies location permission?
How would you design a feature that needs user location data for a core function, while minimizing what leaves the device and remains fully functional if the user denies location permission?