Kotlin is a statically typed language that targets the JVM (and other platforms) which allows writing concise and elegant code while providing very good interoperability with existing libraries written in Java.
The Spring Framework provides first-class support for Kotlin and lets developers write Kotlin applications almost as if the Spring Framework was a native Kotlin framework. Most of the code samples of the reference documentation are provided in Kotlin in addition to Java.
The easiest way to build a Spring application with Kotlin is to leverage Spring Boot and its dedicated Kotlin support. This comprehensive tutorial will teach you how to build Spring Boot applications with Kotlin using start.spring.io.
Feel free to join the #spring channel of Kotlin Slack
or ask a question with spring and kotlin as tags on
Stackoverflow if you need support.