# Kotlin
Confidence: high
Last verified: 2026-05-22
Generation: human_only


## TL;DR

Kotlin (JetBrains, 2011) is a statically-typed JVM language, officially supported for Android since 2017 (Google I/O). Concise syntax, null safety (nullable types `String?`), coroutines for async, 100% Java interoperable. Used by: Google (Android), Pinterest, Uber, Trello.

## Core Explanation

Null safety: `var name: String? = null` — compiler prevents NPEs. Coroutines: `launch { delay(1000) }` — lightweight concurrency. Extension functions: `fun String.isEmail(): Boolean`. Data classes: `data class User(val name: String)`. Kotlin Multiplatform (KMP): share business logic across Android, iOS, Web, Desktop.

## Further Reading

- [Kotlin Documentation](https://kotlinlang.org/docs/)