Job Profil

Job Profile

Mobile Developer

Mobile Developers program applications for mobile devices, such as smartphones and tablets. This can be for Windows, iOS or Android.

Mobile Developer Job Profile

What Do Mobile Developers Do?

Mobile developers are highly specialized IT professionals focused on designing, developing, and implementing applications for mobile devices like smartphones and tablets. Their work is crucial in today’s digital ecosystem, where mobile apps play a central role in our daily lives, from communication and online shopping to navigation and entertainment.

Main Responsibilities of Mobile Developers:

  1. App Development: Mobile developers use programming languages such as Swift for iOS and Kotlin or Java for Android to create native apps for respective platforms. Some developers also use cross-platform frameworks like Flutter or React Native to develop apps that can run on multiple operating systems.

  2. User Interface (UI) Design: Designing user-friendly and appealing user interfaces is crucial for ensuring a positive User Experience (UX). Mobile developers work closely with UI/UX designers to develop intuitive and accessible apps.

  3. Maintenance and Updates: After an app’s release, mobile developers are responsible for its maintenance and regular updates. This includes fixing bugs, improving performance, and adding new features based on user feedback.

  4. Security: Since mobile apps often process personal data, ensuring data security and privacy is an important responsibility of mobile developers. They implement encryption techniques and follow best practices for mobile security to protect user data.

Are Android and iOS the Two Market-Leading Platforms?

One or the other may still remember Blackberry, Windows Mobile or even Symbian on Sony Ericson smartphones. In the meantime, however, Google’s Android (approx. 78% market share in Germany) and Apple’s iOS (22%) have asserted themselves as top dogs – other operating systems for mobile devices can be neglected as a target group nowadays.

Even though the two platforms have become more and more aligned in recent years, both companies continue to rely on their own developer SDK (Software Development Kit) to develop native apps. Native apps are installed directly on an end device and tailored as best as possible to the underlying operating system. Modern Android apps are primarily written in Kotlin (formerly Java), while the iOS SDK is based on Apple’s own Swift language (formerly ObjectiveC). A native Android app cannot run on an iOS device and vice versa. Accordingly, the development of a separate application for the respective platform is necessary. Hybrid app development or web app development can provide a remedy.

Wide Range of App Types: Native, Cross-Plattform, Hybrid, Web,...-Which Is Better?

There is now a huge spectrum of different app types. The following list represents them and should provide a bit more orientation in the jungle of app types:

  • Native App: As already explained, apps are called native if they were developed with the respective in-house Android SDK (Koltin, Java) or iOS SDK (Swift, ObjectiveC) for a single platform. Certainly, they are the most common app type.

  • Cross-platform app: Cross-platform apps are mobile apps that share a large part of the code base and are usable on both mobile and possibly other platforms (such as in any web browser).

  • (Progressive) Web App (PWA): They can be considered as a mobile-optimized website. No installation on the device is necessary, but hardware functionalities, such as the camera or GPS, can only be used to a very limited extent.

  • Hybrid app: We speak of a hybrid app when working with a hybrid app development framework – one of the best-known representatives here is React Native. In this case, the app user is led to believe that the app is native. Under the hood, however, it is an interface implementation that abstracts from the underlying operating system and provides a uniform basis for Android and iOS on which the actual app is created. The native UI elements such as buttons or input fields are usually re-implemented by the hybrid framework. Within the hybrid framework, an app can then be created for Android and iOS at the same time using a programming language (in the case of React Native, it is JavaScript; in the case of Flutter, the Dart language). The level of abstraction chosen by the framework ultimately influences the flexibility of the hybrid app developer. In addition to React Native, Flutter, Cordova, Xamarin and Ionic also belong to the hybrid app frameworks.

Kotlin Native also provides additional tools for sharing code between different platforms: For example, parts of the business logic of an app, such as complex calculations or communication with a server, can be implemented in Kotlin, a native component (library) generated for each platform and used there. However, the UI implementation, among other things, must still be implemented natively.

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Native App vs. Cross-Platform App Development - What Are Experiences and Recommendations?

In recent years, a wide variety of companies have increasingly jumped on the cross-platform app development bandwagon. Instead of developing separate Android and iOS apps, their goal was to maintain only one code base, reach market maturity faster, and ultimately save costs. But even the pioneers Facebook and AirBnB have now switched back to native app development despite significant investments in e.g. React Native, because the promises could not be kept. More info on the exact reasons can be found here.

Google released Flutter, the first version of a new cross-platform toolkit, in December 2018. We’ve compiled our first impressions in the following blog post: How Flutter works under the hood and why it is game-changing

We have always been developing various prototypes and products for customers using Flutter. Flutter is always evolving and improving. A big advantage of Flutter is the easy integration into an existing Android/iOS app, so that the use of Flutter can be tested experimentally for one or a few new features. For a prototypical implementation to validate a new business/product idea, Flutter is well suited in many cases.

Whether we advise you to use Flutter – or an alternative cross-platform technology – depends on your specific project, its scope and your willingness to take risks (Flutter is still in its infancy). From our point of view, it is always worth a thorough evaluation. Indicators that speak strongly in favor of native app development are, for example, communication with external hardware via Bluetooth, WLAN or similar, an excessive integration and adaptation of the usual camera functionality or a comprehensive offline capability of the app.

If you are designing an enterprise app for the B2B environment, we recommend evaluating exactly whether they really need to support Android and iOS – due to the presence of both target groups – or whether they can even limit themselves to one platform if necessary. The acquisition costs of a few Android devices, for example, are usually out of proportion to the development costs for another platform (iOS).

Life Cycle of a Mobile App - What Tasks to Consider?

Whether you develop an app yourself or have an app created, it goes through different phases and life cycles – many of them ideally parallel and iterative. However, pure development work is not enough for a successful establishment on the market.

At the beginning there is the definition of the target group and the elaboration of a unique selling proposition compared to the possibly already existing apps of competitors. Based on this, we recommend a user-centered elaboration of the UX concept in the form of wireframes, followed by a graphic elaboration of the UI design. In this way, initial assumptions can be validated iteratively and corresponding user feedback can be incorporated before a single line of code is created.

The app concept, including the design, then serves as the basis for selecting the technology for app creation. As described above, there are many different ways to implement an app idea. In most cases, an app collects a large amount of data, which is stored centrally in a backend system. Accordingly, a certain security concept must be defined and implemented in order to store the data securely. This information then flows into the corresponding system architecture. With this information, agile development work can then finally be started.

At this point, we refer to our two thematically relevant blog articles for more detailed information:

  • Insights into creating world-class Bluetooth connected mobile apps.
  • Set up your Android project for success


During the implementation and development of an app including the backend, there are some repetitive tasks, such as the deployment (“installation”) of the backend on the server or the creation and publication of the app artifacts in the app stores Google Play and iTunes. However, these and other steps can be automated in a so-called Continuous Integration and Continuous Delivery pipeline (CI/CD). Large parts of the quality assurance – described in detail below – can also be integrated into this automation to ensure the highest product quality at all times.

As soon as the first product version – a so-called Minimum Viable Product (MVP) – is ready, it can be evaluated with the first alpha/beta testers. Accordingly, the release of new app versions can be controlled in a very fine-grained manner. For example, the latest version can initially only be rolled out to beta testers in Germany. If the results are completely satisfactory, the target group can be steadily increased. In addition, it is always possible to create a dedicated app variant for certain markets, such as the USA or Asia.

Lastly, there is the question of how potential users become aware of your app in the first place. The need for marketing should not be underestimated, because the app market is large. Here, of course, advertising can be placed on the relevant platforms. Likewise, appropriate press relations and organic SEO optimization are recommended. Even your app entry in the app stores can be optimized accordingly. If you have done your homework accordingly and the app appeals to the target group and is also implemented in a technically high-quality manner, you may be able to enjoy having your app prominently placed in the stores as “App of the Week” or similar.

How Does Quality Assurance and Control Work in App Development?

Quality assurance and control are an elementary part of our development process. In order to limit manual effort to the important tasks and to constantly guarantee the highest quality, these are implemented from the beginning as part of a so-called Continuous Integration and Continuous Delivery (CI/CD) pipeline: a sequence of measures and analyses checks each project from the first line of code as well as every further change automatically. Changes are developed in isolation, analyzed, and only applied to the project if the check is successful.

In concrete terms, this sequence looks as follows:

  • The code base must compile without errors.
  • Static code analysis: review of changes for potential error sources, consistent code style, and best practices.
  • Automated unit and UI testing: must all be error-free with 60-80% code coverage (depending on your requirements per project; some portions of code cannot be tested automatically).
  • Manual four-eye review of changes by another developer – changes are annotated with any comments, accepted or rejected.
  • Automated deployment of the new app version for internal use.
  • Execution of manual integration tests using a growing test script to check all business requirements.

Different milestones have different levels of requirements. This can ensure that a beta version already meets all manual integration tests, while an internal version does not yet need to go through the manual testing process, for example, to efficiently run experiments. However, there will be no public version that has not been put through its paces and subjected to stress tests.

Should an unexpected problem occur despite the above measures, each project is equipped with appropriate monitoring and reporting. This allows us to react quickly to any errors that occur and to solve them.

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Sören Elser ElevateX GmbH

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Sören Elser

Co-founder of ElevateX GmbH and your contact for the strategic use of freelancers.