Kotlin

Join the Kotlin Track
Kotlin is a pragmatic programming language for JVM and Android that combines OO and functional features and is focused on interoperability, safety, clarity and tooling support.
Join the Kotlin Track
Track mentors

17 Mentors

Our mentors are friendly, experienced Kotlin developers who will help teach you new techniques and tricks.
Track students

5,397 Students

Join thousands of students who have enjoyed learning and improving their skills by taking this track.
Track exercises

64 Exercises

Hundreds of hours have gone into making these exercises fun, useful, and challenging to help you enjoy learning.

About Kotlin

fun getGreeting(): String {
    return "Hello, World!"
}

Kotlin was designed and developed by JetBrains, the company behind IntelliJ. It is a language that runs on the JVM which can target versions 6+ (including the Android platform). JetBrains wanted to use a statically typed language which can remove Java boilerplate code, provide modern functional paradigms, and had seamless two-way Java interoperability with their existing codebase. The JVM already had alternate languages like Groovy and Scala but neither fit the bill with their desired criteria, so they built Kotlin.

Kotlin syntax is similar to Scala and Swift but pulls in the best-of-breed features from other languages such as C# and Groovy. Kotlin took a pragmatic approach at features included in the language by only providing functionality that has been proven to be useful for developers. With this decision they implemented a subset of features of Scala with the intent that it will provide more maintainable code with an easier learning curve for developers looking for a "better Java".

JetBrains has a dedicated team of developers working on Kotlin with the codebase available on Github.

Join the Kotlin track

Exercism is a great website

The reviews are incredibly helpful because they help me see things that I missed, learn about new ways and sometimes interesting discussions that can add a fun twist to maybe a simple problem.

Relaxed. Encouraging. Supportive.

Meet the Kotlin Track mentors

Once you join the Kotlin language track, you will receive support and feedback from our team of mentors. Here are the bios of a few of the mentors of this track.

Avatar of James Landrum

James Landrum James Landrum

I jumped on the Kotlin train back in 2014 after learning about it being a better alternative to the awesome RetroLambda and have been a massive fan since.
Avatar of Dennis Hartrampf

Dennis Hartrampf https://github.com/DennisHartrampf

I have 7+ years experience as software developer, mainly using Java, recently also Kotlin ♥. I'm a fast learner and eager to explore new technologies. I'm also a believer in agile software development, team work and Clean Code.
Avatar of Sinuhe Jaime

Sinuhe Jaime https://github.com/sierisimo

I'm a geek doing a lot of things, including Kotlin. I've using the language for 3 years now but still learning everyday
Avatar of Severin Rudie

Severin Rudie https://github.com/Baron-Severin

I'm a full time Android developer at Mozilla, and I've been working professionally in Kotlin for about 2.5 years now. Kotlin mentor, Rust student.
Avatar of Adrian Spanu

Adrian Spanu https://github.com/aspanu

I work as a software engineer full time. Although I've never worked professionally in Kotlin, I've really enjoyed the language and I generally use it for interview problems or personal projects. I'm looking forward to helping others with it as I learn along myself.
Avatar of Jacob Andersen

Jacob Andersen https://github.com/simpleauthority

I've been using Kotlin for smaller projects for about a year. I find its simplicity and expressive nature very refreshing. I'm ready to help you bring your Kotlin skills to the next level.
Fun. Challenging. Interesting

Community-sourced Kotlin exercises

These are a few of the 64 exercises on the Kotlin track. You can see all the exercises here.

Word Count
medium
conditionals
integers
loops
maps
strings
Two Fer
easy
conditionals
strings
ISBN Verifier
medium
integers
loops
strings
Space Age
easy
conditionals
floating point numbers
Flatten Array
medium
stacks
strings
RNA Transcription
easy
loops
maps
strings
Passionate. Knowledgeable. Creative.

Meet the Kotlin Track maintainers

The Kotlin Maintainers are the brains behind the Kotlin Track. They spend their spare time creating interesting and challenging exercises that we can all learn from. We are incredibly grateful for their hard work. Here are the bios of a few of the maintainers of this track.

Avatar of Mike Gehard

Mike Gehard

Long time software developer, recovering chemical engineer. I love helping folks along their path because I learn something new every time.
Avatar of Sam Warner

Sam Warner

I am a software developer and consultant working for Black Pepper Software, a software company based in Leamington Spa, England. I'm a recent Computer Science graduate from the University of Warwick, and love all things to do with computers!

Get started with the Kotlin track. As with everything on Exercism, it's 100% free!

Join the Kotlin Track