Mobile Development Interview Questions
Practice iOS (Swift, SwiftUI, Core Data, ARC) and Android (Kotlin, Jetpack Compose, Coroutines, Room) interview questions, plus mobile networking, push notifications, and app-store policies.
Frequently Asked Questions
What topics show up in an iOS interview?
Expect Swift fundamentals (value vs reference types, ARC and retain cycles, optionals, generics, protocols), SwiftUI vs UIKit (state property wrappers, view lifecycle), concurrency (async/await, actors, structured concurrency), persistence (Core Data, SwiftData), networking (URLSession, background sessions), the app lifecycle (state restoration, background tasks), and at senior levels - architecture (MVVM, TCA, modularization) and performance (Instruments, memory graph).
What topics show up in an Android interview?
Kotlin fundamentals (coroutines, flows, scope functions, sealed classes), Jetpack components (ViewModel, LiveData/StateFlow, Navigation, Room, WorkManager), Compose (state, side effects, recomposition), the activity/fragment/process lifecycle, dependency injection (Hilt), and at senior levels - modularization, baseline profiles, and ANR/crash debugging. Background-work rules (Doze, foreground service types) come up often because they keep changing.
Should I learn React Native / Flutter for mobile interviews?
Only if the role explicitly targets cross-platform. Most mobile teams hire for native depth (Swift or Kotlin) because cross-platform tools still require native escape hatches for performance, accessibility, and platform features. If you're applying to companies built on RN (Expo, Shopify, Discord) or Flutter (Google, BMW), study the bridge / new architecture (Fabric + JSI + TurboModules) and the Dart isolate model.
How important are app-store policies in interviews?
More than candidates expect. Apple's App Store Review Guidelines, Privacy Manifest (Required Reasons API), App Tracking Transparency, and Sign-in with Apple have all caused real rejections. Google Play's foreground-service types, runtime permissions, and Play App Signing matter on Android. For senior roles, knowing the failure modes saves the team from emergency rework.
What concurrency model should I focus on?
On iOS, Swift Concurrency (async/await + actors + structured concurrency, replacing GCD for new code). On Android, Kotlin Coroutines + Flows on the right Dispatcher (Main / IO / Default) with viewModelScope and lifecycleScope. Both ecosystems have moved decisively away from manual thread/queue management - interviewers care that you understand cancellation, structured scopes, and main-thread safety.
How do mobile system-design interviews differ from backend ones?
Backend system design focuses on horizontal scale and consistency. Mobile system design adds: offline-first sync (CRDTs, last-write-wins, vector clocks), background execution rules per OS, push delivery (APNs / FCM payload limits, priority), client-side caching and storage tiers, conflict resolution, and the unique constraint that you cannot force-update users - so APIs and DB schemas must support old clients indefinitely.