Posted by David Winer, Kotlin Product Manager

When we announced Kotlin as a supported language for Android, there was a tremendous amount of excitement among developers. Since then, there has been a steady increase in the number of developers using Kotlin. Today, we’re proud to say nearly 60% of the top 1,000 Android apps contain Kotlin code, with more and more Android developers introducing safer and more concise code using Kotlin.

During this year’s I/O, we announced that Android development will be Kotlin-first, and we’ve stood by that commitment. This is one of the reasons why Android is the gold partner for this year’s KotlinConf.

Seamless Kotlin on Android

In 2019, we focused on making programming in Kotlin on Android a seamless experience, with modern Kotlin-first APIs across the Android platform. Earlier this year, we launched a developer preview of Jetpack Compose, a modern UI toolkit for Android built using a Kotlin domain-specific language (DSL). We also incorporated coroutines into several of the flagship Jetpack libraries, including Room and Lifecycle. Finally, we brought Kotlin extensions (KTX) to even more major Google libraries, including Firebase and Play Core.

On the tooling side, we strengthened our commitment to Kotlin in Android Studio and the Android build pipeline. Significant updates to R8 (the code shrinker for Android) brought the ability to detect and handle Kotlin-specific bytecode patterns. Support was added for .kts Gradle build scripts in Android Studio, along with improved Kotlin support in Dagger. We worked closely with the JetBrains team to optimize support for the Kotlin plugin, and make the Kotlin editing experience in Android Studio fluid and fast.

Better Kotlin learning

This year we’ve also invested in quality Kotlin on Android learning content.

We released two free video learning courses in partnership with Udacity: Developing Android Apps in Kotlin and Advanced Android in Kotlin. This content was also released as the Codelab courses Android Kotlin Fundamentals and Advanced Android in Kotlin, for those who prefer text-based learning. The popular Kotlin Bootcamp for Programmers Udacity course was also published as a Codelabs course, helping provide a Kotlin foundation for non-Kotlin developers. Kotlin-based instructional Codelabs were also created for topics including Material Design, Kotlin coroutines, location, refactoring to Kotlin, billing in Kotlin, and Google Pay in Kotlin. It hasn’t been just about new content: we've updated Kotlin Codelab favorites to take advantage of important features such as coroutines.

Looking ahead

In 2020, Android development will continue to be Kotlin-first. We’ve been listening to your feedback, and will continue partnering with JetBrains to improve your experience with Kotlin.

This includes working with JetBrains to improve the Kotlin compiler over the next year. Our teams are making the compiler more extensible with a new backend, and making your builds faster with a significantly faster frontend. We’re also working with many of the largest annotation processors to make compilation faster for Kotlin code. You can also expect more Kotlin-first updates to Android, including more Jetpack libraries that make use of Kotlin features such as coroutines.

Thank you for letting us be part of your app development journey this year. We look forward to continuing the journey with you in 2020.