Hire the Top 3% of Freelance Mobile App Developers

Mobile App Developers: A Business Essential in Skyrocketing Demand

The global mobile app market is booming: Standing at $228.98 billion as of 2023, it is expected to reach more than $567 billion by 2030. Companies like Apple, Alphabet (Google’s parent company), and Microsoft—those with significant mobile investments—consistently top the list of the most profitable companies worldwide. Large corporations and small applications alike require expert app developers who can rapidly launch applications, add new features, and debug and maintain existing services.

Choosing a qualified app developer in the current market is no easy feat. More businesses are adopting mobile-first strategies, but since 2015, there has been an ongoing shortage of app engineers for those trying to hire a mobile app developer. In addition to this competition, there is often an overwhelming volume of applicants; companies must quickly and carefully secure the ideal candidates.

In this hiring guide, we examine the crucial attributes that top mobile developers need whether they are junior or senior engineers, and whether they are working on an iOS, Android, or cross-platform application. With these helpful pointers for writing job descriptions, conducting interviews, and assessing applicants, you’ll figure out how to hire app developers to boost your company’s profits.

What attributes distinguish quality App Developers from others?

The caliber of a company’s chosen developers frequently determines the outcome of an app project. And there are many qualifications to consider when identifying top candidates: general technical abilities, soft skills, and platform-specific factors (i.e., proficiency with Android languages, iOS languages, or cross-platform frameworks).

General App Developer Skills: Technical Abilities and Soft Skills

First, all app developers must have technical abilities and soft skills since they work across the full stack of app development and must collaborate with many partner teams.

The required technical abilities depend on an app’s platform and coding languages. However, there are a few standard proficiencies you should look for in all candidates: An understanding of back-end programming, UI/UX design and implementation, and app architecture is crucial for any mobile app developer. They should be strongly versed in at least one mobile development language or framework (i.e., Java, Kotlin, Swift, Objective-C, React Native, Flutter, or Xamarin).

If targeting multiple device types is a top priority for your project, candidates familiar with responsive design—those prepared to implement an app across a variety of screen sizes and devices, including phones, tablets, and even televisions—may best serve your goals.

Soft skills must complement technical abilities because app developers work with many partners, including quality assurance engineers, designers, product managers, and other developer teams. And, at smaller companies or during times of transition, an app developer may have to wear those different hats, leading a product’s design, roadmap, and testing. Look for candidates who can effectively communicate, problem-solve, and collaborate with stakeholders. It is a bonus if a developer is familiar with the user experience journey and can speak the languages of product managers and designers.

Languages for Android Developers: Java and Kotlin

You may choose between various programming backgrounds when hiring Android engineers: Many developers are familiar with Java, others know Kotlin, and some may have experience with both languages.

Java is a general-purpose language released in 1996. Because of its durability, adaptability, and platform independence, Java suits complex applications with big codebases. Veteran Android developers with many years in the field have likely worked as Java developers; Java experts may have a few extra years of experience compared to Kotlin developers and may be better versed in general or back-end concepts.

However, many Java experts are also staying up to date with Google’s preferred language for app development: Kotlin, an Android-specific language released in 2016. Kotlin is developer-friendly, making writing code easier and more effective. If you are creating a new Android app from scratch, you should likely hire a developer proficient in Kotlin.

Both languages have distinct merits and are in wide use among Android engineers. Moreover, they are fully compatible (programmers can use Kotlin and Java in the same project), and you may want candidates skilled in both. If you are unsure which language best suits your app, read more about Kotlin versus Java developers here.

Languages for iOS Developers: Swift and Objective-C

Similar to Android development, iOS development may involve Swift or Objective-C programmers. And while some engineers may only know one language or the other, many iOS developers know both (in particular, many Objective-C developers have learned Swift). It is also possible to use Objective-C and Swift in the same project, as they are fully compatible.

Objective-C, an object-oriented language available since the 1980s, has been the default language for iOS development since the first iPhone SDK release in 2008. Though Apple released Swift in 2014 to replace Objective-C, Objective-C is still relevant: Objective-C developers are a fit in cases where you need to support old OS versions, legacy applications, large or old codebases, or C/C++ library integration.

Swift is a quick, secure, and continually expanding language intended to speed up and simplify the creation of iOS apps. Look for skilled Swift developers if your project’s priorities include the need to improve performance, developer speed, app memory, or project scalability.

Frameworks for Cross-platform Developers: React Native, Flutter, and Xamarin

Building mobile applications that can function on different operating systems (e.g., iOS and Android) is known as cross-platform development. In this case, programmers use frameworks to write code once and deploy it across several platforms—a productive way to create mobile apps.

If different platform versions of your application have few differences and can share code, hiring cross-platform developers can have various upsides, including:

• Reduced development time.
• Cost savings and fewer expended resources.
• Easier app maintenance and code reusability.

Though cross-platform development has advanced considerably in recent years, it may not suit every project. Native apps are preferred in cases requiring hardware-specific feature support or complex graphics, as a cross-platform approach could impact performance and detract from the user experience. Also, some developers prefer to focus on either iOS or Android development.

If you decide that cross-platform developers are the best choice for you, there are three popular frameworks that candidates should know:

• React Native – Released in 2015 by Meta, React Native can emulate native design patterns well and is commonly used by many startups and large companies alike.
• Flutter – A newer framework released by Google in 2017, Flutter can build platform-friendly designs quickly and is catching on among developers due to its many advantages.
• Xamarin – Xamarin was released in 2011 and acquired by Microsoft in 2016; while it has strong performance capabilities, it faces native design challenges, and fewer developers work with the technology due to its limited popularity and community support.

Your choice between React Native developers, Flutter developers, Xamarin developers will depend on your project priorities (e.g., performance, native design, community support).

How can you identify the ideal App Developer for you?

It is vital to consider your unique use case and the expertise it requires when searching for a mobile app developer for hire. For instance, if you are building an e-commerce app, your engineer should have experience creating apps with strong security features and integrating payment systems. Or, if you are building a social networking app, you’ll want a developer who has experience with complicated social features like messaging, commenting, and liking.

The first step here is to specify your problem statement and the resulting skills gap to fill—this is crucial to communicate your requirements to applicants. Consider the scope, price, and schedule of your project, as well as any specific technology needs or constraints. You should also consider the level of expertise needed to accomplish your goals.

Considering Mobile App Schedules and Timelines

The length of a mobile app development project can vary significantly based on various elements (e.g., the size and complexity of the app, the functionality needed, and the development platform used). A more complicated app with specialized features and integrations may take months or even years to develop compared to a simple app with basic capabilities.

And a project’s timeline may affect the type of developer you hire (i.e., a contractor, freelancer, or full-time engineer). Your budget, schedule, project specifications, and personal preferences will impact this decision. Regardless of which path you choose, it is critical to thoroughly investigate applicants, verify their qualifications, and define clear expectations from the start of the project.

Differentiating Between Junior, Mid-level, and Senior App Developers

There are many varying levels of expertise to consider when choosing an app developer. Some mobile app engineers have been around since the first iPhone SDK was released, while others are fresh to the app development world:

• Junior developers often have fewer than two years of experience and require further training and direction to advance their careers.
• Mid-level developers typically have two to five years of experience and can handle more difficult jobs independently.
• Senior developers usually have more than five years of experience, a thorough grasp of best practices for app development, and the capacity to manage a team.

Multiple factors come into play when deciding what level of expertise your app requires, including project budget, size, and deadlines. A junior developer may be a good fit if you are working on a small project or have a limited budget. For a complex project or tight deadline, a senior developer can best ensure the project is finished on time and meets high-quality standards. And a highly talented mobile architect who can help direct your app development approach over time may be worth investing in if you are building a long-term team.

How to Write an App Developer Job Description for Your Project

Your job description will attract and filter the most suitable candidates to apply for your role. A mobile app developer job description should include:

• The necessary qualifications, including education, training, experience, and any desirable credentials.
• Any distinctive features of the business or project that would be alluring to potential applicants.
• The duties and expectations that will come with this role.

Mobile app developer postings may take different forms depending on whether you are searching for an Android, iOS, or cross-platform developer. Though you should tailor requirements to the app’s platform, any mobile developer should have experience with back-end systems, app architecture, user interfaces, and programming languages.

You may use a general mobile app developer job description template or a specialized Android or iOS template to iterate on and refine your ideal posting.

What are the most important App Developer interview questions?

Asking the correct questions and carefully assessing a candidate’s answers will help you determine their technical and cultural fit. Mobile development is a wide umbrella covering many areas of expertise, and you must prepare for the interview process to hire app developers suited for your use case successfully.

You may start your interview with some general mobile app interview questions to ensure that a candidate understands core concepts such as mobile data use, design approaches (e.g., localization and internationalization), and common pitfalls. However, you should tailor your interview based on your custom considerations, such as app architecture, whether or not you also plan to target web delivery, and your desired app platform (i.e., iOS versus Android versus cross-platform).

Architecture is an important part of any app development strategy. Unless a candidate is interviewing for a junior role, they should be familiar with common mobile architectures such as clean architecture, MVVM, and functional and reactive programming:

What is the MVVM design pattern, and when would you use it?

Regardless of whether they are creating an Android or iOS app, developers should be familiar with the Model-View-ViewModel (MVVM) pattern. MVVM separates application layers (e.g., separating views from business logic), resulting in code that is easier to maintain, test, and reuse. The MVVM design pattern is a suitable architecture for many small or medium applications.

Many businesses target app delivery across mobile and computer devices. When this is the case, it may be unclear whether a native or hybrid app offers the best approach. You may want a developer to advise you on your overall app development strategy:

What are the advantages of native apps over hybrid apps?

Most candidates should be familiar with the differences between native and hybrid apps. A comprehensive answer should discuss the pros and cons of each app type. The main benefits of native apps are better performance, more reliable access to device hardware, and greater security. The candidate should be able to explain how native apps can provide a better user experience by taking advantage of platform-specific features and delivering faster load times. On the other hand, an applicant might recommend building a hybrid app when you are working with a small team or need to prioritize development speed.

If you already know you will focus on a native app (i.e., Android or iOS) or use a certain hybrid or cross-platform framework, you should focus your questions on your technology of choice. For example, when hiring for Android, you might ask about data binding because it can be challenging to debug and execute correctly:

What is Android data binding?

The Android Data Binding Library is a package that enables programmers to connect UI elements in layouts to data sources in the architecture of their apps. With data binding, developers can reduce boilerplate code, increase performance, and simplify UI code maintenance. However, since data binding adds logic to UI files, it can make debugging and testing tricky, and not all developers support this approach. Candidates should be able to describe the core functionalities, advantages, and drawbacks of data binding and how to use it in an Android app.

Companies searching for iOS or Android developers may find these resources useful:

• 20 Essential Android Interview Questions and Answers
• 14 Essential iOS Interview Questions and Answers

For those targeting cross-platform or hybrid apps, ask questions specific to the frameworks you are considering working with. For example, a business building a cross-platform application with React Native may choose questions from a React Native interview questions guide.

Why do companies hire App Developers?

App development spans a breadth of platforms, skills, and business use cases. You may be wondering “Exactly what does an app developer do?” App developers design, create, and maintain mobile applications to meet Android, iOS, and cross-platform needs. They use various tools and technologies and collaborate across disciplines (e.g., design, quality assurance, and product), and they map a project’s requirements and goals into tangible product features.

After an app’s launch, a mobile developer offers ongoing support, like coding app updates and integrating the newest hardware and operating systems. They can also advise on app store optimization and troubleshooting to ensure the right people find and use the app.

Modern businesses depend heavily on mobile apps, and a well-designed app can give a company a considerable competitive advantage. Your company can grow income, engage clients better, and find new customers with the aid of an app developer.

We have discussed a variety of subjects regarding the hiring process for mobile app developers, from relevant technical proficiencies to crafting a job description and interview questions. The approach outlined in this guide will empower your company to find a knowledgeable and experienced app developer who can build a profitable and user-friendly mobile app.

The technical content presented in this article was reviewed by Mukhammad Ali Toshboev.