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July 29, 2025

Ship, Share, and Win: The Kotlin Multiplatform Award at Shipaton 2025

There’s nothing quite like the thrill of shipping an app and turning an idea into something real that people can use. This summer, you’ve got the perfect chance to capture that feeling at RevenueCat Shipaton 2025 — a two-month global hackathon focused on launching new mobile apps (August 1 to September 30). And for Kotlin […]

July 28, 2025

When Tool-Calling Becomes an Addiction: Debugging LLM Patterns in Koog

I was testing my agent built on Koog, JetBrains’ open-source framework for building AI agents in Kotlin. I fed it a task from SWE-bench-Verified, a real-world GitHub issue that tests whether AI can actually write code. For the first 100 messages, everything looked promising. The agent methodically explored the codebase, identified bugs, wrote test cases, […]

July 17, 2025

Ktor 3.2.2 Is Now Available

The Ktor 3.2.2 patch release brings a critical fix for Android D8 compatibility, along with some minor enhancements and bug fixes. 🚀 Get started Ready to explore Ktor 3.2.2? Start building your next project today with our interactive project generator at start.ktor.io. Your feedback and contributions are always welcome! 🔗 Get Started With Ktor | […]

July 17, 2025

Breaking to Build: Fuzzing the Kotlin Compiler

At JetBrains, we care about Kotlin compiler quality. One powerful way to test it? Fuzzing, an approach that feeds programs unexpected, often random, inputs to uncover bugs that traditional tests may miss. It may sound chaotic, but it works, especially for complex software like compilers. In a previous post, our colleagues introduced kotlinx.fuzz, a powerful […]

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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