Kotlin

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Kotlin for Backend

Spring support, Java interop, coroutines.

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Kotlin for Server

Spring support, Java interop, coroutines.

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Kotlin for Backend

A simple way to boost your coding joy.

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Kotlin for Server

A simple way to boost your coding joy.

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Kotlin for Backend

A simple way to boost your productivity.

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Kotlin for Server

A simple way to boost your productivity.

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Latest news

October 3, 2025

Amper Update, October 2025 – Compose Hot Reload and UX Improvements

Amper 0.8.0 is out, with Compose Hot Reload, a customizable Kotlin compiler version, new JavaScript and Wasm platforms, and many other improvements to both the IDE and CLI experience. Read on for all of the details, and see the release notes for the full list of changes and bug fixes. To get support for Amper’s […]

October 2, 2025

Koog × A2A: Building Connected AI Agents in Kotlin

If you’ve ever tried building a system of multiple AI agents, you’ve probably run into the problem. It starts simple enough: You’ve got one agent writing blog posts, another proofreading them, and maybe a third suggesting or generating images. Individually, they’re effective. But getting them to work together? That’s where things might start falling apart. […]

September 24, 2025

The Kotlin AI Stack: Build AI Agents With Koog, Code Smarter With Junie, and More

AI is changing how we build software, and Kotlin is ready to meet that change by empowering developers to build AI-powered apps and by enhancing the developer experience through AI-based tools. This post explores both angles: the tools for developing AI-powered apps, both from JetBrains and from the community, and the ways Kotlin is evolving […]

September 23, 2025

Ktor Roadmap and Previews

Like in previous years, we have been working on the Ktor roadmap, and we want to thank everyone for their contributions and feedback to help us prioritize our areas of development for Ktor! The OpenAPI and WebRTC support is already in preview since Ktor 3.3.0. Check out the What’s New section for a full overview […]

Kotlin blog

Why Kotlin?

fun main() {
    val name = "stranger"        // Declare your first variable
    println("Hi, $name!")        // ...and use it!
    print("Current count:")
    for (i in 0..10) {           // Loop over a range from 0 to 10
        print(" $i")
    }
}

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Kotlin in action

McDonald's leverages Kotlin Multiplatform (KMP) for their global mobile app, enabling them to build a codebase that can be shared across platforms, removing the need for codebase redundancies.Kotlin Multiplatform

AWS opted for Kotlin over Java for Amazon Quantum Ledger Database (QLDB) thanks to its expressiveness and structured concurrency. They rewrote QLDB in Kotlin, enhancing the user experience, benefiting from its development workflow, and adopting it fully for server-side development.Server-side

Philips utilizes Kotlin Multiplatform in its HealthSuite digital platform mobile SDK. With KMP, they accelerated the implementation of new features and fostered increased collaboration between Android and iOS developers.Kotlin Multiplatform

Adobe Experience Platform chose Kotlin for server-side development because of its concise syntax, async capabilities, and interoperability with Java. This shift boosted productivity and improved the developer experience, replacing Java for real-time services.Server-side

By sharing over 80% of logic across iOS and Android, Forbes now rolls out new features simultaneously on both platforms, keeping the flexibility to withhold or customize features based on the specific platform.Kotlin Multiplatform

Atlassian adopted Kotlin for the Jira Software cloud, leveraging its Java compatibility for seamless integration and minimizing migration challenges. Kotlin's ease of use improved developer productivity and boosted team satisfaction and efficiency.Server-side

Share code on your terms and for different platforms

Simplify the development of cross-platform projects with Kotlin Multiplatform. It reduces time spent writing and maintaining the same code for different platforms while retaining the flexibility and benefits of native programming. Kotlin applications will work on different operating systems, such as iOS, Android, macOS, Windows, Linux, watchOS, and others.

Learn about Kotlin Multiplatform

Kotlin + AI

JetBrains is investing in AI models tailored for Kotlin, providing open data, benchmarks, and AI-native tooling integrated into your workflow.

At the same time, Kotlin makes it easy to build your own AI-powered features with seamless backend integrations and a growing ecosystem.

What you get with Kotlin + AI

Strong support across JetBrains AI tools like AI Assistant and Junie
Robust functionality for building AI-powered apps on the JVM
Native integration with tools like Spring AI and LangChain4j
Open data and benchmarks for better code generation

Learn about JetBrains AI Build AI apps with Kotlin

Build your own AI agents with Koog

Koog is JetBrains’ new Kotlin-native framework for creating powerful AI agents that run locally, interact with tools, and automate complex tasks. Whether you’re developing a simple chat assistant or an advanced multi-step workflow, Koog gives you full control with clean Kotlin code – no external services are required. Build, extend, and experiment with AI agents entirely in Kotlin.

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Big, friendly and helpful community

Kotlin has great support and many contributors in its fast-growing global community. Enjoy the benefits of a rich ecosystem with a wide range of community libraries. Help is never far away — consult extensive community resources or ask the Kotlin team directly.

Kotlin Foundation

Actively supports community efforts in developing the Kotlin ecosystem.

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Start using Kotlin today!

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