Mobile Developer Interview Questions UK: 8 Real Questions and What Interviewers Want

Most Mobile Developer interviews in the UK follow a pattern, and knowing it beats guessing. Below are eight questions from our bank of 16, each with a note on what the interviewer is really after.

Eight Mobile Developer interview questions, and what the interviewer is thinking

1. What are the trade-offs between native development, React Native and Flutter, and how would you choose for a new app?

Why they ask: Choosing the right approach is a core decision for any mobile developer.

2. How do you manage state in a mobile app, and which patterns or libraries have you used?

Why they ask: State management is a daily architectural concern, and bad choices become costly.

3. How do you design a mobile app to work offline and sync reliably when connectivity returns?

Why they ask: Reliable offline behaviour is a hallmark of a quality mobile product.

4. How do you handle authentication and secure storage of tokens in a mobile app?

Why they ask: Mobile security mistakes expose user data and can breach UK GDPR.

5. Walk me through how you would set up CI/CD for a mobile app, including testing, signing and release to the stores.

Why they ask: Mobile releases have extra complexity, so they check pipeline knowledge.

6. Users report that your latest release drains battery and the app has dropped from 4.5 to 3.8 stars. What do you do?

Why they ask: They want to see calm, data-led handling of a reputation-damaging incident.

7. Tell me about a time you shipped a mobile app or major feature, from planning through to release.

Why they ask: They want to understand your ownership across the full mobile delivery lifecycle.

8. What does a typical day as a mobile developer look like, and why does mobile development appeal to you?

Why they ask: They want realistic understanding and genuine motivation.

A sample answer to question 1

What are the trade-offs between native development, React Native and Flutter, and how would you choose for a new app?

Native development in Swift or Kotlin gives the best performance, immediate access to new platform features and the most platform-authentic UI, but means two codebases and usually two skillsets. React Native uses JavaScript or TypeScript and renders real native components, so it suits teams with web experience and allows high code sharing, though it relies on a bridge or the new architecture's JSI and some features need native modules. Flutter uses Dart and draws its own UI with the Impeller engine, giving highly consistent visuals and strong performance, but it produces larger app sizes and can feel less native without effort. I'd choose by looking at the team's skills, the budget and timeline, how demanding the app is on hardware features such as AR, Bluetooth or heavy animation, and the long-term maintenance plan. For a content or transactional app with a small team, cross-platform is usually sensible. For a graphics-heavy or deeply platform-integrated product, I'd go native.

Common mistake to avoid: Declaring one always best; Ignoring team skills

Want the rest?

Full model answers, key points and common mistakes for all 16 questions are on the Mobile Developer interview questions page. The first five are free, no sign-up needed.