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Kotlin interview questions

Kotlin interview questions and online tests were prepared by our specialized team of professionals. We have a range of Kotlin coding tests for junior, middle, and senior-level developers.

DevSkiller Kotlin interview questions are powered by the RealLifeTesting™ methodology. This methodology is completely unique because it tests the candidate’s skills through real-world problems rather than algorithmic puzzles or riddles. Finding your next Kotlin developer is easy with DevSkiller and our Kotlin online tests.

Also try:
Java programming interview questions

Android
MIDDLE
Tested skills
Duration
41 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Android

Code gaps

assessing knowledge of Android, Kotlin

Programming task - Level: Medium

Android | Kotlin | RecyclerView | To-do List - Create a simple to-do list where each item is a list item in the RecyclerView.

Android
SENIOR
Tested skills
Duration
58 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Android

Code gaps

assessing knowledge of Android, Kotlin

Programming task - Level: Hard

Android | Kotlin, C | JNI Magic - Implement the JNI functionality that enables you to call the Base::getBaseComponent method having a Client instance only.

Android
MIDDLE
Tested skills
Duration
61 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Android

Code gaps

assessing knowledge of Android, Kotlin

Programming task - Level: Medium

Android | Kotlin | Notepad app - Complete basic functionalities of a note-taking application using RecyclerView.

Android
JUNIOR
Tested skills
Duration
53 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Android,

Code gaps

assesing knowledge of Android, Kotlin and Java

Programming task - Level: Easy

Android | Kotlin | Employees Application - Complete app that displays a list of people responsible for different areas in the company like IT or Payroll.

Kotlin
JUNIOR
Tested skills
Duration
95 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Kotlin

Programming task - Level: Easy

Kotlin | Spring Boot | Money Heist - Implement two methods according to the requirements to get all the necessary information from the database.

Java
JUNIOR
Tested skills
Duration
34 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Java, Spring Boot

Programming task - Level: Easy

Java | Spring Boot, Kotlin | Orders microservice - Implement a backbone of the RESTful miscroservice.

Android
MIDDLE
Tested skills
Duration
39 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Android

Programming task - Level: Medium

Android | Kotlin | ConstraintLayout Animation - Implement layout elements animations using ConstraintLayout API.

Android
SENIOR
Tested skills
Duration
75 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Android

Programming task - Level: Hard

Android | Kotlin | Image Fetch (KitKat + TLSv1.2) - Adjust the MainActivity implementation so that the OkHttp client supports TLS 1.2, even if it has been disabled by the Operating System.

Android
SENIOR
Tested skills
Duration
75 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Android

Programming task - Level: Hard

Android | OpenGL ES Demo - The objective of this task is to check the candidate's knowledge of GLSL ES 100.

Kotlin
MIDDLE
Tested skills
Duration
70 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Kotlin

Programming task - Level: Medium

Kotlin | Orders Analyzer | Find an average ordered quantity for every weekday - Implement a method that will analyze orders dataset and return a map with total ordered quantity of a product for every weekday

Mobile Developer
SENIOR
Tested skills
Duration
100 minutes max.
Evaluation
Automatic
Test overview

Programming task - Level: Hard

iOS | Swift | Conference App Senior - Implement a network service that is used to interact with the server.

Programming task - Level: Hard

Android | Async call from native to Java via JNI - Provide the missing JNI part of the native-Java communication combo that fulfills the certain requirements.

Android
SENIOR
Tested skills
Duration
45 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Kotlin, Android

Programming task - Level: Hard

Android | Kotlin | Async call from native to Java via JNI - Provide the missing JNI part of the native-Java communication combo that fulfills the certain requirements.

Kotlin
MIDDLE
Tested skills
Duration
70 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Kotlin

Programming task - Level: Medium

Kotlin | Orders Analyzer | Find an average order value for every weekday - Implement a method that will analyze orders dataset and return a map with an average total order value

Recommend roles for our Kotlin interview questions and online tests

  • Junior Kotlin developer
  • Middle Kotlin developer
  • Senior Kotlin developer
  • Junior Android developer
  • Middle Android developer
  • Senior Android develoepr
  • Junior Java developer
  • Middle Java developer
  • Senior Java developer
  • Mobile developer

How our Kotlin coding tests work

DevSkiller Kotlin coding tests are powered by the RealLifeTesting™ methodology. The methodology works by asking candidates to answer questions and solve problems that they would have to deal with in the real world. Gone are the days of reciting old code or solving academic algorithmic puzzles. This method of testing will provide true and objective insight into your candidate’s skills. Learn more about your candidate’s coding skills, critical thinking, and time-management skills with Kotlin interview questions and online tests.

Key features

  • Gain insight into your candidate’s actual coding ability not just their academic knowledge
  • Convenient remote testing that can be sent anywhere in the world, anytime
  • The RealLifeTesting™ methodology offers a greater user experience where candidates can use their own IDE, clone to GIT, run unit tests, and access Stack Overflow/Github/Google for research.
  • Robust tools that prevent plagiarism and ensure test accuracy
  • Observe the candidate’s undertaking of tests in real-time
  • Non-technical friendly automated results
  • Kotlin coding test available for junior, middle, and senior-level Kotlin developers

Skills covered in our Kotlin interview questions

  • Kotlin
  • Collections
  • Maven
  • Android
  • Android SDK
  • ConstraintLayout
  • Legacy
  • Okhttp
  • SSL
  • TSL
  • REST
  • HNI
  • JVM

What to look for in Kotlin developers

Kotlin was first released in February 2016. It is an open-source statically typed programming language that targets JVM, Android, JavaScript, and Native. Kotlin is a concise programming language and has both object-oriented and functional constructs. It can be used for any kind of development – server-side, client-side, and Android. The programming language is inspired by other existing languages such as Java, C#, JavaScript, Scala, and Groovy.

Kotlin is one of the most in-demand languages today. Java and Kotlin’s interoperability means that a background in the popular Java will serve your Kotlin candidates well. It’s also important to verify the candidate’s knowledge of Kotlin’s safety features, most notably their understanding of ‘null-safety’. Finally, any previous work in developing Android mobile or web applications is a good sign for your Kotlin developer candidates.

Build your own custom Kotlin coding tests

Do you want to build your own custom tests? No problem. The DevSkiller task wizard lets you build custom tests using your own codebase. You can select the languages, skills, and technologies you want to test. Then, choose the scope, difficulty, and test duration all while observing in real-time. Finding your next Kotlin developer has never been easier with DevSkiller and our Kotlin coding tests and interview questions.

Like the look of our Kotlin interview questions but need more?

Interested in sending your first Kotlin coding test invitation but still not 100% convinced? That’s fine, we understand that making any financial commitment for your company is a big decision. Instead of listening to us, why not listen to what one of our many satisfied customers has to say:

CodeValue:

CodeValue is a dynamic software development, UI/UX design, and consulting services firm. Before switching to DevSkiller, their screening process consisted of a phone interview with HR followed up with a technical phone interview then a test and technical interview. After that, there was still another interview with HR and the hiring manager before an offer was made. The biggest obstacle they wanted to overcome was the number of unnecessary technical interviews that took place. Once CodeValue successfully implemented DevSkiller, they were able to reduce the time to hire by approximately 50% while hiring 2.8x more developers from the same candidate pool.

“DevSkiller is easy to use and friendly.” – Olga Berger – Lead recruiter & sourcing specialist at CodeValue

Frequently asked questions

How do you prevent plagiarism in your Kotlin coding tests?

Plagiarism is taken very seriously at DevSkiller and as such, we have a number of robust anti-plagiarism tools in place to ensure all test results are accurate. Screen recording to check if the candidate is looking at a different screen when undertaking a test. We also use a range of social listening tools, check the candidate’s IP address, and use live pair notifications. Our plagiarism detector checks the candidate’s entered code, question duration, and the way each question was answered. All of the answers are automatically cross-referenced with every answer that has ever been logged in our system. If there is a match between your candidate’s answer with another that has been logged, then it will be flagged and we can categorically confirm that the answer was plagiarized.

What’s the duration of DevSkiller Kotlin coding tests?

The duration of tests is flexible. We have a number of pre-defined Kotlin coding tests that have a set duration. Alternatively, you can opt to write your own tests or set the time limit of individual questions within a test.

Do I need to be a programmer to use DevSkiller?

We made DevSkiller as simple and as automated as it can possibly be. Our ready-to-use tests prepared by IT experts allow non-technical users to verify the technical skills of the candidates screened. If you have a technical person on-site, you can prepare a test from scratch.

How long does it take to set up DevSkiller?

Sending your first Kotlin coding test can be done in as little as five minutes. Our wide selection of junior, middle, and senior-level Kotlin online tests means that you can start testing your candidates right after you set up your account.