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How to hire a Mobile Developer

Mobile developers build the apps your users carry on their phones. Some build native apps for iOS or Android. Others build cross-platform apps with React Native or Flutter. In many markets, most people use the internet mainly on a phone. There, a mobile developer shapes what millions of users see. A good or bad hire shows up in app store ratings, crash rates and how many users stay.

Screen Mobile Developer applicants
Mobile Developer

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What is a Mobile Developer?

A Mobile Developer builds apps that run on phones and tablets. Some build natively for iOS or Android. Others use a cross-platform framework that targets both. The job is different from web work in a few ways. Releases go through app store review, and some users never update. The phone may be offline or low on battery. Screen sizes and OS versions vary a lot. Platform rules control permissions, notifications and what runs in the background.

Also called
iOS Developer, Android Developer, Mobile App Engineer
Function
Software engineering
Level
Junior to senior individual contributor
Reports to
Engineering Manager or Mobile Tech Lead
Common stack
Swift and SwiftUI; Kotlin and Jetpack Compose; React Native or Flutter
Next step
Senior or Staff Mobile Engineer, Mobile Lead, or Engineering Manager

The hiring challenge

Mobile resumes hide how deep a person's platform skills go. A candidate with "3 years of React Native experience" may never have written a native module. They may never have handled background tasks or platform permissions. A strong iOS developer may know nothing about Android layouts. So your interview needs to test the platform skills your product needs. General mobile knowledge is not enough. Mobile apps also have their own problems: speed on low-end phones, how the app works offline, and app store releases. Web developers rarely think about these.

What to look for in a Mobile Developer

Four traits matter. Platform depth: do they know the basics of their platform, like lifecycle, memory and permissions? Or do they only know the framework on top? Performance awareness: do they think about app size, startup time and battery use, mainly on low-end phones? Feel for the user: do their apps feel smooth and native? Or do they work but feel wrong? Release discipline: do they know app store review, versioning and staged rollouts?

This matters more when most of your users are on Android, often on cheap phones with little memory and storage. Test for experience making apps fast on low-end phones. Test for offline-first design, since the network is patchy outside big cities. Also test for comfort with apps in many languages if your users do not all speak English.

Common mistakes when hiring Mobile Developers

Thinking cross-platform means they can skip the platform. A React Native or Flutter developer still needs to know how each platform behaves. That covers push notifications, background tasks and device permissions. If they have never touched native code, they get stuck when the framework falls short.

Not asking about real devices. An app can run well on a simulator and still fail on a phone. A candidate who only uses simulators may never have faced low memory, slow networks or odd screen sizes. Ask how they test, and whether they test on real phones.

Ignoring app store experience. Getting an app through review takes practice. So do versioning and staged rollouts. A candidate who has only built internal apps may struggle with public releases.

Key skills for a Mobile Developer

  • Platform fundamentals (iOS or Android)
  • Cross-platform fluency (React Native or Flutter)
  • State management
  • Performance optimization (memory, battery, app size)
  • Release engineering and app store processes
  • Offline-first design
  • Debugging on real devices
  • User experience sensitivity

What a great interview looks like

Coding

"Build a paginated infinite list with pull-to-refresh."

Voice

"Tell me about a mobile bug that was hard to reproduce. How did you find it?"

Voice

"Tell me about a time you made an app faster on a low-end phone. What was the problem and what did you do?"

Scenario

"Your app crashes for 5% of users, but you cannot make it crash on your phone. How would you find the cause?"

Voice

"A feature works one way on iOS and another way on Android. How do you handle that? Give me an example."

You can use these questions in Goodfit as they are, or edit the questions and the scoring for your team.

Recommended interview process

  1. 1

    Round 1: AI Voice Interview15 to 20 min

    Questions on platform depth and app performance, plus a walk through a past project.

  2. 2

    Round 2: Coding Assessment60 min

    Build a mobile feature with real limits, such as pagination, offline handling or platform-specific behavior.

  3. 3

    Round 3: Engineering Manager Interview45 min

    Talk about the release process, how they work with others, and team fit. Only for candidates who passed Rounds 1 and 2.

In Goodfit, the AI interview runs the first round for every applicant. Skill tests, coding tests and roleplays can run in Goodfit too. Your team reads the scorecards and joins for the later conversations.

FAQ

Mobile Developer hiring questions

What does a mobile developer do?
They build and ship the app. They build screens and navigation. They connect APIs and decide what happens when the network drops. They manage local storage and state. They handle permissions, push notifications and deep links. They keep app size and battery use low. They write tests and prepare store releases. They also fix crashes reported from phones they cannot touch. Supporting many OS versions and phone models is a normal part of the job every day.
What is the difference between native and cross-platform development?
Native means building each app separately with its own tools. That is Swift for iOS and Kotlin for Android. Native gives the best speed and full access to phone features. It also supports new OS features right away. Cross-platform, usually React Native or Flutter, shares most code across both. For a typical app it cuts the work about in half. The cost is some speed, and you wait for the framework to catch up when platforms change. Most products do fine on cross-platform. Apps heavy on graphics or hardware, or that need very fast response, usually do not.
Should we hire an iOS developer, an Android developer, or a cross-platform developer?
It depends on where your users are. It also depends on how much platform-specific work the product needs. Two native specialists give the best result. They cost about twice as much as one cross-platform engineer. A good middle path is a cross-platform engineer who knows one native platform well. They can drop into native code when the framework cannot do something. A cross-platform developer with no native experience is a risk. The problem usually shows up the first time a platform update breaks something.
What skills does a mobile developer need?
They need the platform language and its UI toolkit. They need to handle lifecycle and state, where most mobile bugs start. They need networking that copes with going offline and retrying. They need local storage and cache invalidation. They should watch memory and battery use. They should use crash reports and debug from a stack trace on a phone they do not have. They need to know store releases: signing, provisioning, review rules and staged rollout. And they need accessibility, which matters for both the law and the app stores.
Why is app store release different from web deployment?
You do not control when a fix reaches the user. A web fix is live when the page reloads. A mobile fix goes through store review first. Review can take hours or days, and the store can reject it. Then the fix waits for each user to update, and many never do. So mobile teams need feature flags and server-side settings to change the app without a release. They must support old app versions against current APIs for a long time. They also take regression testing far more seriously than a team that can roll back in a minute.
What qualifications do you need to be a mobile developer?
Many have a computer science degree, but it is not required. Published apps count for a lot here, because anyone can check them. There are clear learning paths for each platform. Many mobile developers taught themselves or moved over from web or backend work. Employers look at apps the person has shipped. They look at crash-free rates if the candidate knows them. They also check that the person can explain lifecycle and state without notes.
What interview questions should I ask a mobile developer?
Ask what happens to unsaved work when the OS kills the app in the background. This shows who understands the lifecycle and who has only memorized a framework. Ask how they would build a screen that works offline and syncs later. Ask how they would support an OS version that is two releases old. Ask about a crash they could not reproduce and how they found it. And ask what they would do about a serious bug found an hour after release.
How do you screen a large number of mobile developers?
Published apps tell you the most and are the easiest to check, so ask for them early. Then give a short exercise on state and lifecycle. Score it on a fixed rubric. This filters better than quiz questions about a framework. For high-volume hiring, run a structured technical talk. Cover offline behavior, the release process and a real debugging story. Every candidate gets the same questions, so you can compare people from very different platforms.

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