In some particular cases, providing a DSL can greatly improve the productivity of your dev team. Java is not the best language to provide such DSL. But Kotlin has tons of features that can help you there.

Coroutines can be a nice abstraction, but sometimes it can work against you. This is especially the case when thread safety becomes an issue. Are there easy alternatives, are there limits?

Kotlin is becoming a mature and established back-end language. The maturity of a language is not only measured by its features but also by its community and ecosystem. Kotlin's ecosystem for server-side development is growing very fast. Coming from the Java development side, Spring would be a default fallback option to build your application. While Spring is also hopping on the Kotlin train, the rest of Kotlin's ecosystem is growing fast. More and more new frameworks are popping up implementing different points of view on how to build your service. Those new frameworks might change our ways of developing back-end applications. Let’s have a look out there!

Do your automated tests serve you well? Or does it seem like they are deliberately getting in a way, slowing down any change? Has the “given”’s preparation become an arduous journey littered with shortcuts?

Kotlin has been the new superhero on the JVM team for the last couple of years now. With significant support from both JetBrains and the community, Kotlin has managed to find a good balance between new features and understandability. However, with great power comes great responsibility.

Do you want to migrate your Java codebase to Kotlin, but are you not sure where to start? And how to do that in small steps? This talk shows you how architecture patterns like hexagonal, vertical slice, and domain driven design can enable you to do just that, while at the same time increasing your code quality!

Project Loom will be a game-changer for the JVM’s concurrency model, delivering ‘reactive’ characteristics out-of-the-box without the need for complex concurrency abstractions. What project Loom tries to achieve is already available in Kotlin through Coroutines. So the nagging question is: What will be the faith of Coroutines once Loom delivers? Will they become obsolete?

Functional programming is gaining popularity and partly because of this people have been switching to Kotlin. Although it fits the paradigm better than Java there is still quite a bit missing to unleash the full power of FP. Arrow is here to fill in the missing bits with things like new data types like Try and Either and Optics. Arrow is the most popular functional programming library for Kotlin. In this talk, we will go through what problems Arrow can solve for you and how it can help you with your everyday programming.

Here I will share my experiences with working with Kotlin on a large very ambitious greenfield inspiring project with a great fast expanding team at bol.com. We started out with building a small monolithic POC with just 7 people and have since grown to a multi-service project with almost 40 people with seasoned professionals, which now consist of developers, business analysts, a designer, and other experts racing to meet the deadline of the end of life of the software that is being replaced.

From emoji generators to multiplayer games, tiny printer drivers, IoT-integrations, or Slack message parsers: prototypes for strange ideas are a great driver for learning opportunities – even just to disprove that something is impossible. I want to share with you the fun and excitement that comes from building something truly exciting, the small ideas that keep us up at night until the first tiny proof of concept has been hacked together. We’ll explore how Kotlin can empower us in making those things, through a blend of language features, libraries, and use cases that you might not come across every day. Even if you're not working on your own silly ideas, you will see some novel approaches to solving problems with Kotlin, presented in such a unique context that they’ll be hard to forget.

In day-to-day programming, it is fairly common to find ourselves writing functions that can fail. Most of the time we throw exceptions on our code and it gets tricky tracking exactly where an exception came from. Using the Kotlin Arrow library, we can easily communicate errors in the application and makes it far easier to manage errors within your domain.

Kotlin is a great choice for working with data and is ideally positioned to power the next generation of data-driven applications. This talk goes over the main pros and cons, and demonstrates that important first step: how to use Kotlin for interactive development with Jupyter Notebooks, so you can explore data and validate new models.

Our team enjoys coding with Kotlin. In fact, we enjoy it so much we are converting existing Java projects to Kotlin. Most of these Java projects use Lombok, which made us wonder: Would it be possible to use Kotlin’s built-in features to get rid of Lombok?