Conference for Kotliners

A conference for everything Kotlin
15. June 2018
Budapest, Hungary
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Meet some of our speakers

  • Dmitry Jemerov
    Dmitry Jemerov Principal Engineer, JetBrains
  • Paco Estévez
    Paco Estévez Facebook UK, Λrrow maintainer, mistake-driven learning
  • Annyce Davis
    Annyce Davis Android Development Manager, Off Grid Electric + Android GDE
  • Eugenio Marletti
    Eugenio Marletti Lead Android Engineer @Clue, Android & Flutter GDE

More speakers coming soon...

Meet our speakers

Dmitry Jemerov


Dmitry has been working at JetBrains since 2003, and has contributed to many projects including IntelliJ IDEA, PyCharm and Kotlin. Up until recently, he’s been leading the team working on the Kotlin plugin for IntelliJ IDEA, and now he’s exploring future evolution directions for the IntelliJ Platform. Dmitry is also a co-author of “Kotlin in Action”.

Paco Estévez


After several years as an Android developer I now work on development tools and infrastracture at Facebook UK. During the cold London nights I contribute to the community to enhance Kotlin with battle-tested constructs from other languages. Λrrow is the foundation we’re building for a functional library ecosystem. Come learn about our progress!

Annyce Davis


Annyce is an Android Google Developer Expert. She has spent the past 7+ years developing applications for the Android ecosystem across multiple form factors. She is also an international conference speaker and author, sharing her knowledge of Android development with others.

Eugenio Marletti


Eugenio is a passionate developer who takes every “it can’t be done” as a personal challenge – and is not afraid to find creative solutions while doing so. He’s been stuck in a love/hate relationship with the green droid since 2011, culminating in him moving to Berlin in 2014 to join Clue as Lead Android Engineer. Lately, he’s been allegedly reported to do be abusing the Kotlin language, when he’s not too busy preaching about how Flutter is “the solution to every problem in life”.

Wolfram Rittmeyer


Wolfram is an Android developer since 2012 and has been blogging about it ever since. He’s very active in the Android community, likes to speak at devfests and conferences and is co-organizer of the GDG, Düsseldorf. He’s an Google Developer Expert for Android and the Google Assistant. Of course not everything is tech. As a family guy Wolfram is a proud father of his two sons Linus and Niklas. Funnily they also prove to be a source of inspiration when it comes to new ideas for tech use.

Gyula Vörös


Gyula is a co-founder and tech lead of Makery. He likes to spend time imagining what the future will look like, and exploring technologies that point in that direction. This is how he met Kotlin in 2013, and has been advocating it ever since, by organizing meetups, blogging, and speaking at conferences. When he is not focusing on tech, he enjoys playing around with his dog, and learning about space travel.

Andrei Chernyshev


Andrei is a senior software engineer at Outfittery, a company providing relevant fashion to men, with the help of intelligent algorithms and machine learning. He’s a huge Kotlin enthusiast and advocate, an active member of the Kotlin User Group Berlin, and is always ready to talk about technologies.

Zhixuan Lai


Zhixuan is part of the Android platform team at Tinder. He is passionate about writing clean code, creating great user experience on mobile/web, and building tools that simplify programming.

One more speaker coming soon...

What Conference for Kotliners is about

Kotliners shape
the future of programming

We’re a conference for everything Kotlin. Our speakers are experts, who will talk about the present and future of the Kotlin ecosystem.

This is the designated meeting point for Kotliners all around the globe, to share knowledge, experiences, and the love of Kotlin.

It doesn’t matter if you just heard about the language, are an expert coder, or work on the ecosystem, you better be here.

This is the place to be if you're interested in





doors open


Welcome speech


Eugenio Marletti

Exploiting Kotlin Metadata + Annotation Processing

When compiling Kotlin code for the JVM, the resulting bytecode doesn’t understand the advanced features of the language – like the difference between `List` and `MutableList`, or `List` and `List<String?>`.

A year ago a prototype was developed to use these “metadata” during annotation processing; today, a few popular libraries (even from Google!) employ it under the hood to take their Kotlin integration to the next level.

Join us to explore what’s possible, and ​have fun digging into some practical examples.

[ sequel to last year’s presentation at Kotlin Night Berlin: “Unleash the secret power of Kotlin Metadata” ]


coffee break


Zhixuan Lai

Taming WebSocket with Scarlet

Despite being a well-established standard for bidirectional persistent connection between client and server, WebSocket is complicated to set up on Android. When Tinder migrated to WebSocket for its realtime chat experience, they developed Scarlet: an extensible Kotlin library inspired by Retrofit that eliminates the boilerplate code required to handle data serialization and specify when to connect and retry. After this talk, you’ll be able to configure Scarlet using many of its plugins and integrate any WebSocket API in 10 minutes.


Dmitry Jemerov

Developing multiplatform projects in Kotlin

In Kotlin 1.2, we’ve added support for developing multiplatform projects. Multiplatform projects allow you to reuse the business logic written in Kotlin between all the components of your application – backend code on the JVM, frontend code in JS, and also mobile apps. The common code is compiled for all platforms and can access platform-specific implementations of APIs and libraries. The platform-specific parts are also written in Kotlin and have access to the full set of features of the corresponding platform.

In this talk, we’ll look at language and IDE features that support developing multiplatform projects, and at the libraries that can be used in such projects. As an example, we’ll study a project that supports isomorphic HTML rendering, or, in other words, reuses the HTML building code between the frontend and the backend.


Lunch break



Annyce Davis

Getting a Grip on GraphQL

GraphQL is a query language for your API. This allows you to interact with your existing web services and databases in a new way. Instead of relying on a predetermined output structure from your API, you can “query” it and choose only the fields that you’re interested in. In this talk, learn what GraphQL is all about and how you can take advantage of it in your applications.

A few key GraphQL terms we’ll cover are:

  • Fields/Types
  • Variables
  • Queries/Mutations

Then we’ll take a look at how you can integrate the Apollo Client library inside of an Android application. GraphQL isn’t going away, so here’s your chance to get a grip on this exciting technology!


Paco Estévez

State of the functional ecosystem in Kotlin: mid 2018 checkup

In this talk we’ll go through several of the new patterns and libraries that the Arrow organization is helping grow in the Kotlin community.

Starting from the perspective of someone without experience in functional languages and idioms, what problems are these functional libraries trying to solve, and how do they compare to existing libraries. Lastly, we’ll go through some of the examples and resources available online for those who work on libraries and infrastructure.


Gyula Vörös

Using GraalVM in the context of Kotlin

Kotlin is a very powerful technology with strong emphasis on multiplatform capabilites. The Kotlin compiler can produce bytecode, JavaScript code and also machine code that runs without a VM.

GraalVM is a new addition to the JVM ecosystem that you can utilize for a wide variety of use-cases. Graal can execute bytecode faster, is a platform for polyglot development and also a native compiler.

In this talk, we will take a look at how these technologies can complement each other.


Coffee break


Wolfram Rittmeyer

Kotlin DSLs

One of the things that makes Kotlin development easier to what we had with Java is the ability to use Kotlin’s features to create domain  specific languages (DSLs).
I will start with an introduction into DSLs and specifically with some samples of Kotlin DSLs.

Next you will learn about how they are done. That they are made of many of the simple features you already use in your daily Kotlin development.

Finally I discuss some things I encountered while developing DSLs and that might be relevant if you plan to provide a DSL yourself.


Andrei Chernyshev

Kotlin + Springboot = decision making platform

Outfittery’s mission is to provide relevant fashion to men. In the past we relied purely on our stylists to put together the best outfits for our customers. Right now we are in the process of adding more and more intelligent algorithms to augment our human experts.

This transition to become a data driven company has left its marks on our IT landscape: In the beginning we just did simple A/B tests. Then we wanted to use more complex logic so we added a generic data enrichment layer. Later we also provided easy configurability to steer processes. And this in turn enabled us to orchestrate our machine learning algorithms as self contained Docker containers within a Kubernetes cluster. It then really took us some time to realize that we actually had built a delivery platform to expose just any pure function that our mad data scientists come up with – directly into our microservice landscape. Now we just put their R&D experiments directly into production… 🙂

The application that drives this platform was written 100% in Kotlin. Where coroutines, kotlin scripts and DSL’s were smashed together to fulfill our very specific needs. This talk will guide you through this journey, explain how this platform evolved along with evolution of Kotlin.


Doors closed


We’ll send you an email when new details are revealed – no spam.

Official partners

About the venue

BMC: Budapest Music Center

The conference will be held at Budapest Music Center, a beautiful and modern venue in the heart of Budapest.

More than 700 events take place in BMC every year, with half of them being classical, contemporary, and jazz concerts. BMC is also the home of Eötvös Contemporary Music Foundadtion, which educates, supports, and promotes young talent.

BMC is a prestigious conference center, with excellent acoustics and equipment, in walking distance from the Danube river.

Why Budapest?

Budapest, located in the heart of Europe, has it all: a thriving and ever-growing tech community, scenic architecture and sights, relaxing spas, booming food scene, and epic parties. And we’re pretty close:

  • only an hour from Berlin, Warsaw, Vienna, or Prague
  • only 2 hours from Paris, London, Rome, or Amsterdam
  • only 3 hours from Barcelona, Madrid, Dublin, or Tel Aviv

Cultural mission

We build digital services used by millions all around the world. We’ve been using Kotlin in production for more than 2 years now, both for Android and backend. Kotlin changed the way we work, so we decided to give back, and help the community to grow – this is why we started the Kotliners movement. We also orchestrate trainings, run monthly meetups, and publish blog posts around the language.

Do you have any questions? Let us know!


Co-Founder @ Makery

Co-Founder @ Makery