Kotlin is a statically typed, general-purpose programming language. You can utilize it for developing the latest Android and iOS apps without getting disturbed by problems such as ecosystem and portability. Generally, when a Java developer starts looking for a break into iOS development, Kotlin is their first choice.

Google has announced it as an official language for Android development, followed by Java. Hence, many organizations are getting themselves prepared for hiring Kotlin developers.

While we talk about hiring your next Kotlin mobile app developer, you would be preparing yourself to interview candidates. But that does not mean that you will have to grip the subject before hiring the candidate. Neither you must mug up the subject before interviewing the developer. All you need is a bunch of questions. Yes! This article will help you find some of the advanced Kotlin questions you can ask your applicant during the interview.

A Kotlin developer’s main job will be developing applications. Some of the other responsibilities include:

• To make sure that the applications have an effective UI design
• Take care that the UI designs are of high quality and easy to use
• To ensure that the apps should remain error-free
• Keep an eye on the applications regularly
• Check and confirm the quality of the code and maintain the live apps regularly
• Work with Kotlin as well as Java. They need to shift the Java projects to Kotlin or execute them both in the development processes

Also, you need to check whether the candidate has the following skills:

• Expertise in Kotlin as well as Java programming languages
• Expertise in designing Android applications
• Proficiency in testing techniques
• Understanding of debugging and troubleshooting
• Excellence in UI design

Apart from this, you can also keep a note on the following skills:

Language Proficiency

It is observed that Android development is a bit troublesome and has its own Software Development Kit to develop android apps. However, Kotlin is one of the two languages which is essential to create an Android app. So when you are searching for a Kotlin developer, make sure you choose one with appropriate experience in language proficiency.

App Architecture

The basis of any Android app development is the app architecture. So, your candidate should be experienced with the app architecture and know how to build that architecture from the start according to your organization’s needs. Hire a Kotlin developer that can create an app architecture for better user interactions and user experiences.

User Interface

Your candidate should be good at making the best UI or user interface because that is the only thing that makes an app interesting. The user interface acts as a gateway to the application. So while hiring your next Kotlin developer, you should consider someone who can integrate UI components into app architectures to create a smooth experience.

Data Management

While you are hiring your next Kotlin developer, you should look for someone who understands database management.

Once you have the list of required skills, see that if your candidate has them. If you find him/her eligible for your company, move on to the next step.

After you check their resume, skills, and responsibilities, test their practical knowledge with the help of some online Kotlin code editors. These tools will help you in choosing the best candidate while trying him on the platform. You will also get to know that the candidate is practically sound for working on real-life projects or not.

Here is a list of some senior Kotlin developer interview questions you need to see and ask your candidate:

1. Can you execute Kotlin code without JVM?
2. Differentiate between Kotlin’s Variable Declaration Methods
3. What do you understand by structural expressions?
4. What’s the problem with below code?
   val name = "UBUNTU"
   val upperCase = name.toUpperCase()
   name.inc()
5. Can you mention some of the extension methods used in Kotlin?
6. Does Kotlin allow calling Java Functions?
7. Mention the type of strings present in Kotlin?
8. Why doesn’t Kotlin feature explicit Ternary Conditionals?
9. What are constructors, explain their types?
10. Explain the workings of when in Kotlin.
11. How to create an empty constructor for data class in Kotlin?
12. What are Co-Routines in Kotlin?
13. How to initialize an array in Kotlin with values?
14. What Extension Methods does Kotlin provide to java.io.File?
15. How to create a singleton class in Kotlin?
16. Why doesn’t Kotlin Feature Macros?
17. What are Null Safety and Nullable Types in Kotlin?

Here are some of the Kotlin interview questions to ask your candidates and help your company hire one of the best developers. But the thing is, you will have to go through the answers to these questions. This will help you in understanding the answers provided by the candidate. Coding interview tools are also an excellent way to rely on for testing your candidate’s practical knowledge.

Hope you find it helpful for hiring Kotlin developers. Happy hiring!