Apple Interview Questions 2026

Design iCloud Photo Library — 2 billion photos synced across iPhone, iPad, and Mac. Cover: deduplication (perceptual hashing), delta sync (only changed chunks), offline-first with conflict resolution, and privacy — how Apple performs server-side processing without seeing unencrypted photos.

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 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?

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.

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.

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?

Apple is obsessed with privacy. Describe a feature you designed or could design where user privacy was a significant engineering constraint. How did you balance functionality with privacy?

Apple products are known for polish over speed of delivery. Tell me about a time you pushed back on a deadline because the work wasn't ready, and how that conversation went.

Given a BST, find the closest value to a given target. Explain the O(log n) iterative approach using BST properties, and how the answer changes if the tree is unbalanced.

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?

Design an offline-first note-taking app that syncs across a phone, tablet, and laptop, resolving conflicts when the same note was edited on two devices while offline.

Two data centers each think they're the primary for a user's data after a network partition heals — a classic split-brain. How would you design the system to detect and resolve this safely?

In Swift, what is the difference between DispatchQueue.main.async and DispatchQueue.main.sync, and why can calling .sync from the main thread deadlock your app?

An app's cold launch time regressed from 800ms to 1.4s after a release. What's your systematic approach to finding the regression before assuming which commit caused it?