Kotlin

About Kotlin

Kotlin is a statically typed, cross-platform programming language developed by JetBrains, first released in 2016 and adopted by Google as the preferred language for Android development in 2017. Kotlin runs on the JVM (interoperable with all Java libraries), compiles to JavaScript (Kotlin/JS for browser/Node.js), and compiles to native binaries (Kotlin/Native for iOS, macOS, Linux, Windows) — making it a genuine multiplatform language. Kotlin's design goals were to fix Java's pain points: null safety (null pointer exceptions are compile-time errors by default), concise syntax (50% less boilerplate than Java), extension functions, data classes, coroutines for async programming, and smart casts. Kotlin Coroutines are a first-class concurrency abstraction — lightweight structured concurrency that eliminates callback hell without the complexity of reactive streams. Kotlin Multiplatform Mobile (KMM) allows sharing business logic code between iOS and Android while keeping platform-specific UIs. Spring Boot (version 5+) has first-class Kotlin support. Kotlin Server Side (Ktor framework by JetBrains) provides a Kotlin-native async web framework. JetBrains' own products (IntelliJ IDEA, YouTrack, TeamCity) are written in Kotlin. Android's shift to Kotlin-first means virtually all new Android apps are written in Kotlin. Stack Overflow surveys consistently rank Kotlin as a highly loved and well-paid language.