Hire the Top 3% of Freelance Mobile App Developers
Toptal is a marketplace for top app developers. Top companies and start-ups choose Toptal app freelancers for their mission critical software projects.
SingaporeFreelance Mobile App Developer at Toptal Since August 30, 2016
Andrei is an experienced full-stack web developer with almost a decade of experience working with a large variety of technologies—over half of that working remotely. He is equally comfortable collaborating with a team of developers or flying solo. He has worked with satisfied clients from the US, Australia, Kuwait, and Russia.
BelgiumFreelance Mobile App Developer at Toptal Since January 26, 2017
Niels is a seasoned software architect and entrepreneur with over fifteen years of experience. He's a generalist with strong communication and business skills who speaks the language of customers as well as techies. He has extensive experience as a product architect in B2B hi-tech software as well as B2C web and mobile software. Niels enjoys designing and implementing simple solutions to complex problems.
PortugalFreelance Mobile App Developer at Toptal Since April 4, 2014
João is a passionate iOS and Android developer. With strong attention to detail, he has created many great apps and has delivered many projects for millions of users, both startups and big companies. João has worked extensively on back-end and API integrations. A positive attitude allows him to create on his own and in teams.
PortugalFreelance Mobile App Developer at Toptal Since October 30, 2011
As an entrepreneur, Luís understands the importance of proactivity and results, and has learned the meaning of responsibility and accountability. He is more of a generalist than a specialist, though he loves the detail and deep understanding that comes from intense focus and work on development projects.
RomaniaFreelance Mobile App Developer at Toptal Since December 9, 2019
With over a decade of programming experience and over eight years as a business owner, Lorand knows the importance of excellent communication and understanding with a client. He's obsessed with high quality and attention to detail, and he strives to find the best solutions possible. He currently focuses on using Magento or TYPO3 in his projects.
United StatesFreelance Mobile App Developer at Toptal Since October 7, 2019
Chetan is an entrepreneur with nearly a decade of professional experience in software engineering. He has founded a mobile gaming company and released two games, one of which has over 6 million downloads on iOS and Android. Chetan was previously an engineer and researcher at a cutting-edge AI company, and the first engineering hire at a social mobile startup. He can fit easily into any project, delivering products that surprise and delight.
AustraliaFreelance Mobile App Developer at Toptal Since May 6, 2019
In a nutshell, Hugh delivers positive outcomes. When he encounters a problem, he identifies the essential dynamics, hypothesizes a remedy, monitors, and iterates. When the issues extend, impact, or involve others, he acts quickly, focusing on communication and the roadmap. Hugh has over 25 years of experience developing applications and solving problems across a breadth of technical and business domains.
United StatesFreelance Mobile App Developer at Toptal Since July 10, 2018
Andrew is a senior engineer and architect with proven expertise across the full stack. He is always ready to devise an optimal solution for a specific set of problems. He enjoys designing and planning ahead of a project and the implementation that follows, ensuring project requirements are met. Andrew is passionate about constructive feedback and ideas where appropriate. He adjusts well to a variety of programming languages and technologies to provide ideal, long-term platform solutions.
United StatesFreelance Mobile App Developer at Toptal Since June 29, 2017
From payments to maps to real-time updates, ambitious UI/UX, and those ubiquitous QR codes, Eric has built it for startups and enterprises. And he won't get stuck where many engineers make time-wasting mistakes: geospatial data, simple logins for everyone (you too, enterprise SSO), in-app search, time zones, email deliverability, user permissions, and other stuff you shouldn't have to worry about. Eric is proactive and happy to communicate at any level of technical (or non-technical) detail.
United StatesFreelance Mobile App Developer at Toptal Since January 14, 2014
Joshua is an architect, engineer, and scientist with experience building large-scale systems dealing with everything from massive amounts of video data to heavy web traffic. He also has experience breaking monoliths into scalable microservice architectures and going the other way 'round. He's worked for Apple and AOL and has also led a group of 50+ consultants as their chief scientist.
App Developers are full-stack engineers who build and maintain applications across various devices—from working on back-end data collection and app architecture to implementing user interfaces. This guide to hiring App Developers provides tips on defining skill requirements, creating job descriptions, and selecting interview questions so you can identify the best candidate.
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Tripcents wouldn't exist without Toptal. Toptal Projects enabled us to rapidly develop our foundation with a product manager, lead developer, and senior designer. In just over 60 days we went from concept to Alpha. The speed, knowledge, expertise, and flexibility is second to none. The Toptal team were as part of tripcents as any in-house team member of tripcents. They contributed and took ownership of the development just like everyone else. We will continue to use Toptal. As a start up, they are our secret weapon.
Brantley Pace, CEO & Co-Founder
Tripcents
I am more than pleased with our experience with Toptal. The professional I got to work with was on the phone with me within a couple of hours. I knew after discussing my project with him that he was the candidate I wanted. I hired him immediately and he wasted no time in getting to my project, even going the extra mile by adding some great design elements that enhanced our overall look.
Paul Fenley, Director
K Dunn & Associates
The developers I was paired with were incredible -- smart, driven, and responsive. It used to be hard to find quality engineers and consultants. Now it isn't.
Ryan Rockefeller, CEO
Radeeus
Toptal understood our project needs immediately. We were matched with an exceptional freelancer from Argentina who, from Day 1, immersed himself in our industry, blended seamlessly with our team, understood our vision, and produced top-notch results. Toptal makes connecting with superior developers and programmers very easy.
Jason Kulik, Co-Founder
ProHatch
As a small company with limited resources we can't afford to make expensive mistakes. Toptal provided us with an experienced programmer who was able to hit the ground running and begin contributing immediately. It has been a great experience and one we'd repeat again in a heartbeat.
Stuart Pocknee , Principal
Site Specific Software Solutions
We used Toptal to hire a developer with extensive Amazon Web Services experience. We interviewed four candidates, one of which turned out to be a great fit for our requirements. The process was quick and effective.
Abner Guzmán Rivera, CTO and Chief Scientist
Photo Kharma
Sergio was an awesome developer to work with. Top notch, responsive, and got the work done efficiently.
Dennis Baldwin, Chief Technologist and Co-Founder
PriceBlink
Working with Marcin is a joy. He is competent, professional, flexible, and extremely quick to understand what is required and how to implement it.
André Fischer, CTO
POSTIFY
We needed a expert engineer who could start on our project immediately. Simanas exceeded our expectations with his work. Not having to interview and chase down an expert developer was an excellent time-saver and made everyone feel more comfortable with our choice to switch platforms to utilize a more robust language. Toptal made the process easy and convenient. Toptal is now the first place we look for expert-level help.
Derek Minor, Senior VP of Web Development
Networld Media Group
Toptal's developers and architects have been both very professional and easy to work with. The solution they produced was fairly priced and top quality, reducing our time to launch. Thanks again, Toptal.
Jeremy Wessels, CEO
Kognosi
We had a great experience with Toptal. They paired us with the perfect developer for our application and made the process very easy. It was also easy to extend beyond the initial time frame, and we were able to keep the same contractor throughout our project. We definitely recommend Toptal for finding high quality talent quickly and seamlessly.
Ryan Morrissey, CTO
Applied Business Technologies, LLC
I'm incredibly impressed with Toptal. Our developer communicates with me every day, and is a very powerful coder. He's a true professional and his work is just excellent. 5 stars for Toptal.
Pietro Casoar, CEO
Ronin Play Pty Ltd
Working with Toptal has been a great experience. Prior to using them, I had spent quite some time interviewing other freelancers and wasn't finding what I needed. After engaging with Toptal, they matched me up with the perfect developer in a matter of days. The developer I'm working with not only delivers quality code, but he also makes suggestions on things that I hadn't thought of. It's clear to me that Amaury knows what he is doing. Highly recommended!
George Cheng, CEO
Bulavard, Inc.
As a Toptal qualified front-end developer, I also run my own consulting practice. When clients come to me for help filling key roles on their team, Toptal is the only place I feel comfortable recommending. Toptal's entire candidate pool is the best of the best. Toptal is the best value for money I've found in nearly half a decade of professional online work.
Ethan Brooks, CTO
Langlotz Patent & Trademark Works, Inc.
In Higgle's early days, we needed the best-in-class developers, at affordable rates, in a timely fashion. Toptal delivered!
Lara Aldag, CEO
Higgle
Toptal makes finding a candidate extremely easy and gives you peace-of-mind that they have the skills to deliver. I would definitely recommend their services to anyone looking for highly-skilled developers.
Michael Gluckman, Data Manager
Mxit
Toptal’s ability to rapidly match our project with the best developers was just superb. The developers have become part of our team, and I’m amazed at the level of professional commitment each of them has demonstrated. For those looking to work remotely with the best engineers, look no further than Toptal.
Laurent Alis, Founder
Livepress
Toptal makes finding qualified engineers a breeze. We needed an experienced ASP.NET MVC architect to guide the development of our start-up app, and Toptal had three great candidates for us in less than a week. After making our selection, the engineer was online immediately and hit the ground running. It was so much faster and easier than having to discover and vet candidates ourselves.
Jeff Kelly, Co-Founder
Concerted Solutions
We needed some short-term work in Scala, and Toptal found us a great developer within 24 hours. This simply would not have been possible via any other platform.
Franco Arda, Co-Founder
WhatAdsWork.com
Toptal offers a no-compromise solution to businesses undergoing rapid development and scale. Every engineer we've contracted through Toptal has quickly integrated into our team and held their work to the highest standard of quality while maintaining blazing development speed.
How much does it cost to hire a mobile app developer?
The cost of hiring a mobile app developer depends on a project’s size and scope, a company’s location, and a developer’s level of seniority. Additional project-specific factors that may raise the price of an app’s development include the integration of payment gateways, the need for customization, and the use of APIs. As a reference point, Glassdoor lists $97,021 as the typical total pay for a mobile applications developer in the United States as of May 22, 2023. App developers can be expensive, but your team can finish its project on schedule and to the required standards with the help of careful research, planning, and budgeting while hiring.
How can your business benefit from hiring a mobile app developer?
There are several advantages to hiring a mobile app developer for your company. First and foremost, hiring app developers gives your company a competitive edge by allowing you to connect with a larger audience via mobile devices. Apps enhance client engagement and retention due to the predominance of mobile devices. Mobile apps can also customize consumer experiences and streamline company procedures; you may incorporate customer service, inventory management, and payment methods into your app. And a mobile app can gather insightful user data and feedback to enhance your product offerings. Overall, employing mobile app developers will help expand your company and enhance consumer satisfaction, inevitably resulting in more sales and profitability.
What do I need to look for when I choose a mobile app developer online?
When choosing a mobile app developer online, experience, technical proficiencies, and soft skills are the primary indicators to inform how successful a developer will be on your team. First, the developer’s background should showcase a portfolio of successful apps relevant to your project goals, including positive references. You may request examples of their work and inquire about their problem-solving and debugging strategies. Second, the developer’s technical abilities must be strong and correlate to the development tools, platforms, and programming languages needed for your project; consider hiring someone committed to remaining current with the newest trends and technologies in mobile app development. Finally, an app developer needs excellent communication and teamwork abilities; it is a green flag if a candidate has a track record of collaborating across product, design, and quality assurance.
Are mobile app developers in demand?
Yes, mobile app developers are in high demand due to the prevalence of mobile device use; mobile apps are necessary for businesses that want to stay relevant and improve user experience. The global mobile app market was valued at $228.98 billion as of 2023 and is projected to more than double through 2030. App giants like Apple, Alphabet (Google’s parent company), and Microsoft dominate the list of the most profitable companies worldwide, but companies of any size can benefit from investing in the lucrative market of mobile apps.
How can I determine if I need a cross-platform or a native application?
Considering your unique requirements and objectives is vital when choosing between a cross-platform and native mobile app. Cross-platform apps employ a single codebase to develop apps for many platforms using frameworks like React Native, Flutter, and Xamarin. Native apps use separate codebases for different platforms, whether targeting Android development (Java and Kotlin), iOS development (Swift and Objective-C), or both. In general, simple programs that don’t need regular hardware contact or high-performance capabilities can be developed more quickly and cheaply through cross-platform development. However, a native mobile app best suits more complex, high-performance apps that interact with hardware or other native apps frequently.
Ahmad is a full-stack mobile and web developer who has built multiple apps released to the Apple and Google Play app stores. He specializes in cross-platform development with React Native and Flutter, and has worked at various companies around the world. Ahmad’s city-based social mobile app placed second in a hackathon organized by the municipality of Izmir in Turkey.
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.
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.
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:
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.
