Android developers are in high demand. With about three billion devices powered by the Google-based mobile operating system, and a 70% market share of all devices worldwide, opportunities for professionals specializing in Android app development services are plentiful.
Salary prospects align with the high demand. Combine that with an industry that offers creative applications for your talents, and an exciting career path awaits you.
But how do you get the gig? Beyond building your resume and applying for Android developer jobs, passing an interview and accurately demonstrating your abilities is a crucial first step. To help you prepare for your Android evaluation, here are 25 Android developer interview questions you can expect to encounter.
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Basic Android developer interview questions
Technical interviewers, including those at EPAM Anywhere, use their interview queries to assess your technical know-how and experience level. The evaluation is also your chance to demonstrate soft skills such as work ethic, problem-solving, and collaboration.
Regardless of your seniority level, you’re likely to be asked about Android development fundamentals and general approaches. We prepared the following essential Android developer interview questions and answers in collaboration with Serhii Kamenkovych, EPAM Anywhere’s Lead Software Engineer and Certified Technical Interviewer.
Considering how much is riding on your responses, it always is a good idea to be prepared, so let’s get started!
1. What are the commonly used languages in Android?
This is one of the more simple interview questions for Android developers, so you should be ready with a list of known languages such as Java, Kotlin, C#, Python, and Groovy. For extra points, you can list some Integrated Development Environments (IDEs) like Eclipse, NetBeans, IntelliJ, and Android Studio.
“Depending on the position details and the candidate’s experience, the interviewer might shift questions to focus on some specific technologies. For example, if the position requires knowledge of Kotlin rather than Java, the interviewer might omit Java questions altogether. However, if the candidate has a proven experience with Java, related questions can still come up.”
2. What is the architecture of Android?
Android architecture features five main components:
- Android Framework
- Android Runtime
- Platform Libraries
- Linux Kernel
Your interviewer may ask such an open-ended question to assess how well you know each layer of the Android stack, as each component critically supports the needs of mobile development.
3. What are the main components of the Android application framework?
The Android application framework provides the underlying libraries that allow developers to use device resources for application creation. For an interview question, be ready to explain some classes such as activity, service, broadcast receiver, and content provider.
4. What are the benefits and disadvantages of Kotlin?
Java is established and widespread, but Kotlin continues to grow in popularity. If asked, use this query to showcase your knowledge and abilities with Kotlin, explaining how it can eliminate NullPointerException (NPE) from code, has cross-platform app development functions, and often has better readability.
“The interviewer will always adjust technical questions to the candidate’s past project experience once that’s established. There’s no need to talk about the difference between RxJava operators if the person has never used them, or Kotlin-Java interoperability if the person started their career with Kotlin and has never handled pure Java or mixed projects.”
5. How are permissions managed in Android?
Android permissions control how users access sensitive data held within the applications. As an Android developer, it is your job to limit information access while maintaining functionality. List some best practices for Android permissions, such as setting default handlers or selecting third-party SDKs that also have limited permissions.
6. What are the launch modes available for the activity in Android?
Launch modes help you launch activities with specific sets of instructions and attendant navigation requirements. There are four launch modes that you should reference if asked this interview question:
Each launch mode has its own role to play in allowing navigation across any possible configuration, so compare and contrast the benefits and drawbacks to achieve full marks.
7. What is the difference between fragment and activity?
The code for an activity is far more in-depth than for a fragment. Be sure to mention to your interviewer that due to the extended work, activities should only be used for swapping entire screens, while fragments are used for everything else. If possible, list some use cases in which you almost always use a fragment rather than an activity (e.g. when you use components or data that must persist across varied activities).
8. What are the examples of design patterns used in Android applications?
Design patterns are reusable templates that solve problems (think repetitive code). When presented with this question in an interview, be sure to outline the common Android pattern categories (Creational, Structural, and Behavioral) and give some use cases. Earn some bonus points by explaining how you resolved a problem from a previous project with a design pattern.
9. What types of Android app architectural patterns are there?
Architecture patterns are applied to structure a project and make it modular. There are three main Android architectural patterns that developers use and that you should mention:
- MVC (Model — View — Controller)
- MVP (Model — View — Presenter)
- MVVM (Model — View — ViewModel)
Since each architectural pattern involves a wealth of information, consider this a more broad coding question. Offer detail when possible, but use this question to show your extended grasp of Android programming.
10. What additional libraries do you use in Android app development?
Libraries let you take advantage of the work of other developers for better performance as you create apps. There are several popular libraries that you can talk about (Glide, Retrofit, Picasso, Dagger, Koin), but take the opportunity to explain the library you prefer or have used in the past with great success.
11. What is PendingIntent in Android?
A PendingIntent passes a future intent to a different application that will perform execution. PendingIntents are a crucial part of the Android framework because they can specify actions to another app. It is good if your answer to this Android coding interview question touches upon implementation details and the new changes within Android 12 regarding mutability.
12. What is a content provider in Android?
A content provider controls access to an app's data. Other applications will use a provider client object, creating an interface to handle communication. As a programming question, be ready to explain how you would access data from a content provider in addition to supplying information on creating a content provider within your own app. Since accessing data can block a main thread, note how you would perform data queries on a separate thread.
13. What is meant by ANR?
As an intermediate interview question, use this opportunity to explain what an Application is Not Responding (ANR) is as well as the steps you could take to avoid an ANR. Mention both trigger conditions (a response to an input, a broadcast receiver does not execute in a reasonable time) and common patterns used for diagnosing ANRs (long calculations occurring on the main thread, synchronous binder calls with another process are taking a long time to return).
14. What kind of services are available on Android?
A service is an application component that does not need a UI to work (think of a music service playing music or downloading files). Services are mechanisms for background work. In your interview, make sure you discuss the three types of services:
- ForegroundService: Operations a user can recognize
- BackgroundService: Operations unnoticed by the user
- BoundService: Bound services that provide a client-server interface for component interactions
The more details you can provide the better, so including information about threads vs services, intent services, or how a service starts, can all help your case.
15. Explain flavors in Android
With this question, the interviewer wants to know if you can differentiate between product flavors and build types, as they are often mixed up. Also, convey how developer customization to apps across different codebases is tedious and causes errors, so using product flavors is ideal since you can create app variants with a single code base. Mention these details in addition to explaining Gradle, as it creates build type variants.
16. How do you handle a long-running process in an Android app?
Processes are defined as long-running by Android if they take longer than 10 minutes to complete (such as large uploads and downloads or user-specified tasks). In such cases, you must create a long-running worker with WorkManager (assuming you can’t chunk workloads).
17. How do you protect an Android app from reverse engineering?
Android application development interview questions will focus on the latest trends and topics. That will include discussions about security and data privacy. With the popularity and open-sourced nature of Android, you need to offer direct methods for protecting user data from reverse engineering. A business always wants to mitigate the negative impacts of security hacks or breaches, so your answers here are important.
Make sure you are well aware of prevention tactics and tools such as tamper detection, ProGuard Assistance, and SafetyNet. List other best practices such as using C++ for important code, securing user credentials, server-side database encryption, and altering Android's shared library loading process.
18. What is Android Jetpack and what are its libraries?
Android Jetpack is a suite of tools and libraries that can help you build high-quality apps. While the software offers many benefits regarding build complexity and writing boilerplate code, it also addresses several challenges such as limiting memory leaks or managing configuration changes. Jetpack offers four categories of components (Foundation, Architecture, Behavior, and UI) and a host of libraries. In the interview, list a few and explain how they helped you in the past.
19. What are the new updates and features in Android 13?
Android 13 is the latest release of the Android mobile operating system, expected to reach platform stability in June/August of 2022. Android 13 beta is already out and offers some quality-of-life upgrades and privacy and security improvements. As an Android developer, it is your job to stay near the edge of continual innovation, so having an awareness of upcoming upgrades is a crucial opportunity to demonstrate your expertise.
20. How do you publish an Android app to the Play Store?
Android job interview questions are not always the hardest, technical-based queries. But this deceptively simple question can include plenty of varied factors about configuring your app and signing release versions. Be prepared to explain some common tasks involved with app publishing.
21. What is needed to run code as coroutine?
This is a more technical Android interview question, and it pertains specifically to Kotlin coroutines. Kotlin creates fluid server-side or mobile applications by providing coroutines at the language level, leading to asynchronous programming. Display your understanding of Kotlin syntax, threads, and sequential code in Android architecture components to impress your interviewer.
22. How do you test an Android application?
As the interview progresses, you will receive more senior-level Android engineer interview questions. Advanced Android interview questions are an opportunity to showcase your advanced knowledge, and also your leadership skills and creativity. In this case, lay out some testing fundamentals to start (functional, performance, accessibility, and compatibility test types), and then shift into a discussion of your preferred testing approaches to demonstrate your problem-solving capabilities.
23. What’s the purpose of RxJava?
Different paradigms help solve different problems, and RxJava helps simplify asynchronous programming. As a top Android interview question, here is your chance to explain your understanding of programming libraries and functional reactive programming in Android. Explain how it can take complex implementation of asynchronous behaviors and simplify mobile programming.
24. What are the benefits of MVVM?
As a recommended architecture approach by Google, MVVM has become a standard in Android development. This question allows you to show an understanding of problems that MVVM solves, knowledge of other styles such as MVC/MVP, the pros and cons of each, and how to choose between them when starting a new project.
25. How do you provide dependencies between different parts of the app?
Persistent avoidance of "dependency hell" is one of the essential parts of clean code. Knowledge of inversion of the control pattern and its different implementations (ServiceLocator, Dependency injection, etc.) can help to provide robust and testable solutions. Be ready to provide possible solutions based on Android SDK and third-party libraries.
Android coding interview questions
A coding task is a mandatory part of the interview for every software engineering level. Usually, it is an algorithmic or practical task that shouldn’t take longer than 10-15 minutes to solve. Technical interviewers try to avoid asking questions like “What will be printed?” since they are looking for engineers, not compilers.
In most cases, you won’t need to follow all the syntactic aspects of your chosen language since there will be no IDE during the interview; if allowed, you can even resort to pseudo-code.
“You should try to make your coding task solution as close to reality as possible. For example, don’t use some magic library function that does everything for you. Instead, try to solve the task yourself.”
The scope of each Android interview question is large and complex, but it serves a purpose: allowing you to share your talents with the company.
While giving detailed answers to technical questions is important, don’t forget that your presentation of the material itself conveys your skills and abilities. The purpose of reviewing the above-listed questions and practicing your answers is to avoid hesitation, passivity, and nervousness (a common issue for difficult interviews). When you control these reactions with your preparation, you will be well on your way to a long and fruitful career as an Android developer!
“The answers you provide, questions you ask, and the behavior and reactions that you show during an interview are essential to an evaluation of you as a specialist and to making a hiring decision regarding you as a candidate.”
If you want to land a remote job with EPAM Anywhere, check out our open Android developer jobs to explore current work opportunities.
Thanks to Deepan Muthusamy, Java Software Engineer, EPAM Anywhere, for contributing to this guide.