Mobile App Development Interview Questions for 1 Year Experience
40 questions with answers for candidates with 1 year of experience — 16 easy, 24 medium.
What interviewers expect: 1 year experience
With one year of experience, interviewers expect you to have delivered features in a real app. Questions cover state management, navigation, forms, error handling and local storage, plus debugging stories. You may get a take-home assignment building a small app with an API. Explain your exact contribution, the problems you hit and how you solved them.
This set is weighted towards Mobile Development Fundamentals (7), Dart and Flutter Basics (6), App Store and Play Store Publishing (6), Testing, Performance and CI/CD (6).
State management basics Navigation and deep links Local storage and caching Debugging and fixing crashes
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01
Write a Dart model class with fromJson and toJson.
Keys help Flutter match widgets to existing elements and state when the widget list changes. Without keys, Flutter matches by type and position, so reordering or removing items in a list of stateful widgets can attach state to the wrong item. Use ValueKey with a unique ID for list items, UniqueKey to force recreation, and GlobalKey rarely, for accessing state across the tree such as a Form.
Deep links open a specific screen in your app from a URL. Custom schemes like myapp://order/42 work but are not verified. Verified HTTPS links are App Links on Android, using assetlinks.json, and Universal Links on iOS, using an apple-app-site-association file on your domain. When verified, the link opens your app directly instead of the browser. The routing library, like go_router or React Navigation linking, maps URLs to screens.
Metro is the JavaScript bundler for React Native. It resolves modules, transforms code with Babel, and serves the bundle to the app during development with Fast Refresh. For release builds, it produces a minified bundle that is compiled to Hermes bytecode. It supports platform-specific extensions, asset handling and configuration in metro.config.js for things like SVG transformers or monorepo setups with watch folders.
05
How do you handle account deletion requirements in mobile apps?
Both major stores require apps that let users create accounts to also let them delete their account from within the app, and the Play Store also requires a web link for deletion requests. Implement a clear settings option, confirm the action, call a backend endpoint that deletes or anonymises user data according to retention rules, revoke tokens, clear local data and sign the user out. Document what is retained for legal reasons.
06
Write a release checklist for a mobile app update.
1. Bump version name and build number on both platforms.
2. Run full automated tests and smoke tests on release builds.
3. Verify signing, obfuscation and debug symbol upload.
4. Check new permissions and update store privacy declarations.
5. Update release notes and screenshots if UI changed.
6. Upload to internal track and TestFlight; QA sign-off.
7. Submit for review with reviewer notes and demo account.
8. Start staged rollout at 5 to 10 percent.
9. Monitor crashes, ANRs, reviews and key metrics.
10. Expand rollout or halt and hotfix.
07
What are the main differences between Android and iOS that a cross-platform developer must know?
Navigation patterns differ: Android has a system back gesture while iOS relies on swipe-back and navigation bars. Permissions, notification setup, background execution limits, file systems and store review rules differ. iOS builds require a Mac and Xcode, with signing through certificates and provisioning profiles. Design guidelines differ between Material Design and Human Interface Guidelines, so good cross-platform apps adapt some UI per platform.
08
What are the steps to publish an iOS app on the App Store?
Enrol in the developer program, create an App ID and the app record in App Store Connect, and set up signing with certificates and provisioning profiles, often managed automatically by Xcode or EAS. Archive the release build with an incremented build number, upload it, and test through TestFlight. Complete metadata, screenshots, privacy nutrition labels and age rating, then submit for review. After approval, release manually, automatically or in phased release.
Maestro is an open-source mobile UI testing framework where flows are written in simple YAML, such as launchApp, tapOn "Login" and assertVisible "Welcome". It works with native, Flutter and React Native apps on Android and iOS, handles waiting automatically, and reduces flakiness compared to many older tools. Teams use it for smoke tests of critical journeys in CI because tests are quick to write and readable by QA.
A Future represents a value that will be available later, like an HTTP response. Marking a function async lets it use await, which pauses that function until the Future completes without blocking the event loop. Errors are handled with try-catch. Dart runs on a single-threaded event loop per isolate, so awaiting network calls keeps the UI responsive. Use Future.wait to run independent futures concurrently.
11
What is the difference between ScrollView and FlatList?
ScrollView renders all its children at once, which is fine for short content but uses lots of memory and slows rendering for long lists. FlatList virtualises, rendering only items near the viewport and recycling as you scroll, with props like keyExtractor, initialNumToRender and windowSize. For very large or complex lists, FlashList offers better recycling and performance. Never nest a FlatList inside a ScrollView of the same direction.
12
Write a custom hook that fetches data with loading and error states.
InheritedWidget lets descendants read data efficiently via context and rebuild when it changes, which is how Theme and MediaQuery work. Writing it by hand is verbose. Provider wraps InheritedWidget with a simpler API: ChangeNotifierProvider exposes a ChangeNotifier, and widgets use context.watch to rebuild or context.read to call methods without rebuilding. It is simple and suitable for small to medium apps.
15
Describe a time you had to deliver a feature with incomplete requirements.
Situation: product asked for a referral feature with only a one-line description. Task: deliver in a sprint. Action: I listed open questions, met the product manager for 20 minutes to agree on core rules, built the agreed version with configurable reward values from the backend, and documented assumptions in the ticket. Result: we shipped on time, and later changes needed only config updates instead of a new release.
Since Dart 3, all code is null safe. Types are non-nullable by default, so String cannot hold null while String? can. The compiler forces you to handle nulls with checks, the ?. and ?? operators, or the ! operator which throws if null. The late keyword declares a non-null variable initialised later. Sound means the compiler can trust non-null types completely, enabling optimisations and preventing many runtime null errors.
17
The cart total shows stale values on the checkout screen after items are removed on the cart screen. How do you fix it?
Each screen probably holds its own copy of cart data. Move cart state into a single shared state object, such as a Riverpod notifier or a Cubit provided above both screens, and have both screens watch it. All mutations go through that object, which emits a new immutable state. Derived values like total should be computed from the state, not stored separately, so they can never become inconsistent.
18
A user reports that they cannot find your app in the store on their old phone. Why could this happen?
The app may not be available for their device because the minimum OS version is higher than theirs, the device lacks a required hardware feature declared in the manifest, the app is not released in their country, or the device architecture is excluded. Check the device catalogue in Play Console and the deployment target on iOS. Decide whether supporting that segment is worth lowering requirements.
19
How does token-based authentication work in mobile apps?
The user signs in and the server returns a short-lived access token, often a JWT, and a longer-lived refresh token. The app stores them securely in Keychain or Keystore-backed storage and sends the access token in the Authorization header. When it expires, the app uses the refresh token to get a new one, retrying the failed request. On logout, tokens are deleted and ideally revoked on the server.
BuildContext is a handle to a widget's location in the element tree. It is used to look up inherited data like Theme.of(context), MediaQuery and Navigator, and providers. Each widget's build method gets its own context. Common mistakes are using a context from above a widget that provides data, or using a context after an async gap when the widget may be unmounted; check context.mounted before using it after await.
21
How does navigation work in React Native with React Navigation?
React Navigation provides navigators: native stack for push and pop screens using platform transitions, bottom tabs, drawer and material top tabs. You nest navigators, for example tabs inside a root stack with modal screens. Screens receive navigation and route props or use hooks like useNavigation and useRoute. Version 7 adds a static configuration API for better TypeScript inference and automatic deep link setup.
22
How do you persist state in React Native between app launches?
For small key-value data use AsyncStorage or MMKV, which is much faster and synchronous. Persist Redux with redux-persist or Zustand with its persist middleware, choosing only the slices that need it. Store tokens in secure storage like expo-secure-store or Keychain and Keystore wrappers, never in plain storage. For larger structured data use SQLite through expo-sqlite or an ORM like WatermelonDB.
23
What is a WebView and when is it appropriate to use one?
A WebView embeds a browser engine in your app to show web content. It suits help pages, terms, payment gateway pages or quickly reusing an existing web flow. It is not ideal for core app screens because it feels slower and less native. Restrict navigation to trusted domains, avoid exposing powerful JavaScript bridges to untrusted content, and handle back navigation. Flutter uses webview_flutter and React Native uses react-native-webview.
24
What is the difference between native, cross-platform and hybrid mobile apps?
Native apps are written in platform languages, Kotlin for Android and Swift for iOS, with full access to platform APIs and the best performance. Cross-platform frameworks like Flutter and React Native share one codebase and render native-feeling UI, saving time for two platforms. Hybrid apps, such as Ionic or Cordova, run web code inside a WebView. Choice depends on performance needs, team skills, budget and how much platform-specific UI is required.
25
What is the difference between a debug and release build in mobile apps?
Debug builds include debugging tools, hot reload, assertions and unoptimised code, so they are slower and larger. Release builds are compiled ahead of time, minified, optimised and signed with a release key. In Flutter, debug uses JIT while profile and release use AOT compilation; in React Native, release bundles minified JavaScript precompiled to Hermes bytecode. Always measure performance and test critical flows on release or profile builds.
26
Tell me about an app you published and what you learned from real users.
Situation: I published a notes app with a friend and got about 2,000 installs. Task: improve ratings stuck at 3.6. Action: I read every review, found users disliked losing notes when switching phones, added cloud backup and a clear onboarding screen, and fixed two crashes from Crashlytics. Result: rating rose to 4.4 in two months. I learned to prioritise what users actually complain about over features I assumed they wanted.
27
Integration tests pass locally but fail randomly in CI. How do you make them reliable?
Flaky tests usually come from timing assumptions, shared state, network dependence or slow emulators. Replace fixed delays with waiting for specific conditions, mock or stub network calls with predictable responses, reset app data between tests, and use stable selectors like keys or test IDs instead of text that changes. Give CI emulators enough resources, retry only as a temporary measure, and track flaky tests separately to fix them.
28
Write a go_router configuration with an auth redirect.
Firebase is a mobile and web development platform. Commonly used services are Authentication for email, phone OTP and social logins; Cloud Firestore and Realtime Database for synced data; Cloud Storage for files; Cloud Functions for server code; Cloud Messaging for push notifications; Crashlytics for crash reports; Analytics; Remote Config for feature flags; and App Distribution for testers. FlutterFire and React Native Firebase provide SDKs.
30
What are privacy declarations required by the app stores?
The Play Store requires a data safety form describing what data is collected, shared, encrypted and deletable, plus a privacy policy link and account deletion option for apps with accounts. The iOS App Store requires privacy nutrition labels, a privacy manifest file for the app and listed third-party SDKs describing data use and required reason APIs, and App Tracking Transparency permission before tracking users across apps.
31
How do you implement OTP login with a phone number?
The user enters a phone number, the backend or an auth service sends an OTP via SMS and returns a verification ID. The user enters the code, which is verified to issue session tokens. On Android, use the SMS Retriever or User Consent API to auto-read the code without SMS permissions; on iOS, set the text content type to one-time code for autofill. Rate-limit requests, expire codes quickly and protect against abuse.
32
How do you explain your architecture choices to a new team member?
I start with the problem each layer solves, using one real feature from our app to trace a user tap through widget, state notifier, repository and API, and back to the UI. I share a short diagram and the team's architecture document, then give them a small task touching every layer. I review their first pull request closely and invite questions so they understand the reasons, not only the rules.
Test business logic without widgets. For Bloc, the bloc_test package's blocTest builds the bloc with a fake repository, acts by adding events, and expects a list of emitted states. For Riverpod, create a ProviderContainer with overrides for repository providers, read the notifier, call methods and assert the state. Use mocktail for mocks and keep tests fast, deterministic and independent of the network.
34
How do you make sure your code works before handing it to QA?
I test the happy path and edge cases myself on both Android and iOS, including no network, slow network, empty states, large text sizes and rotation. I write unit tests for logic and run the existing test suite. I review my own diff before raising the pull request and add clear testing notes for QA explaining what changed and what to check, which saves time for both of us.
35
After a release, crash reports show a spike only on one Android OS version. What steps do you take?
Pause the staged rollout to limit impact. Filter crash reports by OS version and device to find the top stack trace, and check behaviour changes for that version, such as permission, background or edge-to-edge rules. Reproduce on an emulator of that version, fix it, add a regression test and resume rollout with a hotfix. Add that OS version to the regular test device matrix.
36
How do you set up CI/CD for a cross-platform mobile app?
On every pull request, run lint, formatting checks, unit and widget or component tests. On merge, build signed Android and iOS release artifacts using CI services such as GitHub Actions, Codemagic, Bitrise or EAS Build, with signing keys stored as secrets. Use fastlane or EAS Submit to upload to internal testing tracks and TestFlight. Automate version numbers, generate release notes and run smoke tests with Maestro.
createState creates the State. initState runs once for setup like controllers and subscriptions; do not use inherited widgets there. didChangeDependencies runs after initState and when inherited data changes. build runs on every rebuild. didUpdateWidget runs when the parent rebuilds with new configuration. dispose runs when removed permanently, where you cancel streams, dispose controllers and timers to avoid memory leaks.
38
What is accessibility in mobile apps and how do you implement it?
Accessibility makes apps usable by people with disabilities. Provide labels for icons and images so screen readers like TalkBack and VoiceOver can announce them, keep touch targets at least 44 to 48 points, support dynamic text sizes, ensure colour contrast, and avoid conveying information only by colour. Flutter uses Semantics widgets, and React Native uses accessibilityLabel and accessibilityRole. Test with screen readers enabled.
39
When would you choose a cross-platform framework over native development?
Choose cross-platform when you need both Android and iOS quickly with a small team, the app is mostly forms, lists, content and API-driven screens, and design consistency across platforms is desired. Choose native when the app needs heavy graphics, deep hardware integration, advanced background processing, newest platform features on day one, or very tight performance. Many companies mix both, using native modules inside a cross-platform app.
Use Jest as the test runner with React Native Testing Library, which renders components and queries them the way users do, by text, role or label. Fire events like fireEvent.press or userEvent, then assert on output. Mock native modules and network calls with jest mocks or MSW. For end-to-end tests on real builds, use Detox or Maestro, which drive the app on emulators and simulators.
Frequently asked questions
What is asked in Mobile App Development interviews for 1 year of experience?
With one year of experience, interviewers expect you to have delivered features in a real app. Questions cover state management, navigation, forms, error handling and local storage, plus debugging stories. You may get a take-home assignment building a small app with an API. Explain your exact contribution, the problems you hit and how you solved them.
How many questions should I practise before a Mobile App Development interview?
Work through all 40 questions here, then the company-wise sets for the employers you are targeting. Quality matters more than count: be able to explain why each answer is right.
Which topics matter most for 1 year of experience?
Focus first on State management basics, Navigation and deep links, Local storage and caching, Debugging and fixing crashes.