Mastering Kotlin

Increased build size and speed

Adding Kotlin and the Kotlin standard library to your project does come with an additional size cost. It's minimal, but it will potentially increase the size of your executable and increase your method count. The extent of this increase can be mitigated by making use of tools, such as ProGuard, which will optimize your code and remove any unused methods added by Kotlin or the Kotlin standard library.

The addition of Kotlin may also slow down your build speeds by requiring additional build steps to compile the new Kotlin code. The amount of slowdown generally depends on how your project is built, how many modules you have, and how much mixing of Java and Kotlin you are doing. It's hard to know the exact impact, ...