To find the best Android app developer, you must ask interview questions that reveal applicants' skills, personalities, and experiences. Unfortunately, creating these questions can be time-consuming, especially if you're unfamiliar with Android development and don't know what to look for in a mobile app developer.
This guide explains what an Android developer is responsible for and provides sample interview questions to ask a potential hire. It also covers how Revelo can help you source Android talent, line up interviews, and guide you through the interview process.
What Is an Android Developer?
An Android app developer uses programming languages and commands to create applications for Android devices. They are also responsible for the following:
- Debugging new and existing application components
- Creating and managing threads of execution
- Collaborating with cross-functional teams to create, test, and ship new features
- Working with outside application programming interfaces (APIs) and data sources
- Continually discovering, assessing, and implementing new development tools
Depending on their skill sets and experiences, Android developers can create various apps, including mobile games and productivity apps. They should also know how to create three basic types of Android apps:
- Native apps are created specifically for Android devices.
- Web apps are responsive versions of sites that can work on any operating system or device since they're delivered through mobile browsers.
- Hybrid apps are combinations of web and native apps wrapped within a native app. As such, users can download hybrid apps from the Play Store.
As an employer, you may want to consider hiring Android developers to create visually appealing and intuitive apps for companies. Their deep understanding of coding, the Android platform, user experience, and user interface design can ensure your apps meet stakeholder and client requirements, are delivered on time, and are continuously improved and updated.
Entry-Level Android Developer Interview Questions
Entry-level or junior Android developers have zero to four years of experience. Due to their limited experience, entry-level Android developers must usually be mentored by mid-level and senior Android developers. They also typically have fewer responsibilities than their mid-level and senior counterparts.
To gauge their growth potential, you should evaluate entry-level developer candidates' fundamental skills and knowledge. Here are some sample junior Android developer interview questions to get you started.
Explain the components of the Android architecture.
This question reveals candidates' Android knowledge of fundamental Android concepts. The ideal answer should cover at least three of these components:
- Activities dictate the user interface and handle the user interaction directed at the smartphone screen. Each activity is a single screen with a user interface. For example, an email application may have an activity class for composing an email, another for showing a list of emails, and another for reading emails.
- Services run in the background to perform long-running applications. For instance, a service may play music while users wait for a module to load.
- Broadcast receivers handle communication between applications and the Android operating system. They respond to broadcast messages from other apps or the system.
- Content providers handle database and data management issues by supplying data from one app to others by request.
- Layouts let developers view hierarchies that control view appearance and screen format.
- Resources consist of external elements, such as constants, strings, and drawable pictures.
- Manifest is the configuration file for the Android application.
What programming languages are used to develop Android applications?
Ask this question to learn about entry-level applicants' basic knowledge and skills. Good responses should cover at least two of the following:
- Kotlin is the official language for Android. It can interoperate with Java and runs on the Java Virtual Machine.
- Java was the original official Android language. Most apps in the Play Store are built with Java.
- C# is similar to Java, making it another great choice for Android app development.
- CSS, HTML, and JavaScript are the building blocks of the internet. Developers can use these languages to create hybrid Android applications using the Adobe PhoneGap framework.
Mid-Level Android Developer Interview Questions
Mid-level Android developers have four to six years of experience. They have more responsibilities than entry-level developers but take fewer leadership and mentorship roles than their senior counterparts.
When hiring mid-level Android developers, you should ask interview questions that assess their proficient understanding of advanced concepts. You should also assess soft skills like problem-solving and the ability to handle complex development tasks.
Below are sample interview questions for mid-level Android developers.
What is the difference between explicit intent and implicit intent?
This question tests candidates' knowledge of advanced Android concepts. A strong answer should look something like this:
Explicit intent specifies the component, and intent provides the external class that will be invoked. In contrast, implicit intent does not specify the component. Instead, intent provides data on the available components that will be invoked.
What is the Dalvik Virtual Machine (DVM) and its importance?
Ask this question to learn more about an applicant's optimization skills. Here's what an ideal answer should cover:
The Dalvik Virtual Machine (DVM) was an Android virtual machine optimized for mobile devices. It optimized the virtual machine for battery life, memory, and performance. It was a vital part of the Android software stack in Android versions 4.4 and earlier versions, often used on mobile devices such as tablet computers and mobile phones. Android Runtime replaced the DVM in 2014.
What are containers and their purpose?
This question reveals the depth of job seekers' technical knowledge. The best answers should resemble the following:
Containers can sort a collection of widgets, objects, and other elements. They can hold anything, including fields, child containers, and buttons. Developers can use containers to isolate mobile apps from the mobile operating system and other applications on the same device. Containerization offers many benefits, including improved content and data security, complete control over the workplace, a native Android experience, and user data privacy. Developers can also use containerization to make two versions of any app: one for work and another for personal use.
Senior-Level Android Developer Interview Questions
Senior Android developers have over six years of experience. They lead and mentor junior- and mid-level developers, collaborate with other developers to continuously improve products, develop high-quality code by reviewing other developers' work, and champion a client-focused environment.
To assess senior-level Android developers' suitability, ask questions that assess their in-depth knowledge, leadership skills, extensive portfolio, and ability to tackle complex challenges in Android app development. Feel free to reference these sample Android interview questions for senior developer questions.
When should a fragment be used over an activity?
This question evaluates the breadth of senior-level Android developers' development knowledge. Here's a model answer:
An activity is the most basic form of an Android application. It represents a single screen with a user interface. Developers can use activities to launch and create other app components, such as passing data between screens and launching a new screen. In contrast, fragments are small bits of code for building user interfaces within activities. Developers usually use fragments to separate complex user interfaces into smaller, more manageable pieces. They can also use fragments to provide a shared user interface between multiple activities or add functionalities to an existing activity.
Explain the serializable and parcelable approaches.
This question tests applicants' ability to code effectively and efficiently. A strong answer should resemble the following:
Serializable code is a standard Java interface for adding override methods. The main problem with a serializable framework is that it uses reflection and is slow. This is because a serializable approach creates a lot of temporary objects and garbage collection. In contrast, the parcelable method is much faster because developers are explicit about the serialization process rather than using reflection to infer it.
How would you troubleshoot a crashing application?
Ask this question to evaluate job seekers' troubleshooting skills and experience. A good answer should look like this:
I would troubleshoot a crashing application by doing the following:
- Reproduce the crash: Attempt to reproduce the crash consistently and note the specific inputs or actions that trigger the crash.
- Check error logs and messages: Look at any log files or error messages generated by the application.
- Review recent changes: Determine whether recent changes, such as configuration modifications or code updates, caused the crash.
- Test on different environments: Try running the app on other operating systems, devices, and network configurations to see if the crash is specific to certain environments.
- Use debugging tools and techniques: Debugging tools and techniques will help the team identify the specific module or line that caused the crash.
- Collaborate with the development team: Work with other developers, including Quality Assurance (QA) testers, to collaborate on troubleshooting.
- Apply fixes and test: After identifying the root causes of the crash, apply appropriate fixes, such as updates to external dependencies and code changes. After implementing the fixes, test the application to ensure the crash has been resolved.
- Monitor and learn: Continually monitor the app's stability and performance even after fixing the crash.
Hire Android Developers With Revelo
If you don't have the time or resources to interview and hire Android developers, Revelo can help. Our Latin American Android developers operate in U.S. time zones and have been thoroughly vetted for English fluency and hard and soft skills. Revelo can also support hiring and onboarding by managing payroll, compliance, and benefits.
Interested in seeing how we can help you? Contact us to learn more about hiring dedicated Android developers to join your team.
