What is Kotlin?

Kotlin is a modern, statically typed programming language that runs on the Java Virtual Machine (JVM) and can also compile to JavaScript or native code. Created by JetBrains in 2011 and officially released in 2016, Kotlin has become the preferred language for Android development (Google announced official support in 2017).

It’s designed to be:

  • Concise — less boilerplate than Java
  • Safe — built-in null safety to avoid NullPointerExceptions
  • Interoperable — works seamlessly with existing Java code
  • Versatile — can be used for Android, backend, desktop, and multiplatform apps

Key Characteristics

  1. Cross-Platform
  • Runs on JVM, compiles to JavaScript, and can produce native binaries via Kotlin/Native.
  1. Null Safety
  • Nullable and non-nullable types (String? vs String) prevent common runtime crashes.
  1. Interoperability with Java
  • You can call Java from Kotlin and vice versa without special configuration.
  1. Modern Syntax
  • Type inference, data classes, extension functions, and smart casts simplify development.
  1. Functional + Object-Oriented
  • Supports OOP concepts as well as functional features like higher-order functions and lambdas.
  1. Coroutines for Concurrency
  • Built-in support for asynchronous programming with lightweight threads.

Why Kotlin is Popular

  • Officially supported by Google for Android — now the default choice for new Android projects.
  • Less boilerplate than Java, making code cleaner and easier to maintain.
  • Safe & expressive, encouraging better coding practices.
  • Ecosystem support — works with Spring, Ktor, Android Jetpack, and many libraries.

Where You Can Use Kotlin

  • Android development (mobile apps)
  • Backend services (with frameworks like Ktor or Spring Boot)
  • Web development (via Kotlin/JS)
  • Desktop applications (using JavaFX or Compose for Desktop)
  • Multiplatform projects (shared code across Android, iOS, and desktop)