Kotlin - Back to School - Episode III of the 2024 Edition

Hello fellow Kotliners!

The next episode of the Kotlin 2024 edition will take place in the Hedwig-Dohm-Hause in Mitte - thank you HU-I!
Please note: This event is unsponsored, therefore food and drinks are not provided and need to be paid for by yourself!

Line-Up:

First Talk:
Testing Kotlin Backend Apps
by Alexey Korneyko

In the realm of backend development, testing plays a pivotal role, influencing speed, reliability, and overall system design. Despite the testing capabilities enabled within the Kotlin ecosystem, antipatterns coming from the Java world often go unchallenged. This talk aims to shed light on these issues, emphasizing the impact on development processes and system architecture. I plan to compare the testability of traditional Spring framework applications with Ktor and Http4k. By setting expectations and requirements for effective test suites, I challenge the conventional practice of dependency mocking. Additionally, I might dive into the opportunities provided by Kotest, highlighting its advantages over JUnit. In conclusion, this talk is not just about testing; it's about optimizing the entire development process and unlocking TDD practices. My main goal is to entertain the audience, but if it can provide a fresh perspective for someone on testing Kotlin backend applications, I'll be happy.

Second Talk:

TBD
by Matthias Geisler

Third Talk:

How to create extensible Kotlin DSLs for existing Json/Yaml configuration languages.
by Jilles van Gurp

While building DSL support for my kt-search library, a Kotlin multi-platform client for Elasticsearch & Opensearch, I had to build support for it's various Json DSLs. for querying, defining mappings, and a few other things. Elasticsearch and Opensearch (Amazon's fork) are both rapidly evolving and this creates a problem: how to handle things that aren't supported by your Kotlin DSL and ensure people can use your DSL with new features. I came up with a nice solution to this problem and this can potentially be adapted to a wide range of Json, Yaml, and other tree like formats used for DSLs. It makes clever use of a few Kotlin language features. In this talk we'll dive a bit into why Kotlin is so nice for so-called internal DSLs and why you should consider creating them for your own frameworks, external DSLs, and libraries that you use. And then we dive into some code to show you how it's done.

Speaker BioL

Jilles van Gurp

Jilles is the CTO of FORMATION, a Java developer since 1995, a Kotlin developer since 2017 using it both on frontend and the backend, and a veteran of this and other meetups.

Matthias Geisler

Matthias is a true believer in (Kotlin) Multiplatform, while engaged in community work as an organizer or speaker for several communities.
Also, Matthias builds a few solutions for KMP like KMock.

Alexey Korneyko

Alexey is a software engineer with over 10 years of experience. He's a
fan of Test-Driven Development (TDD), pair programming, and fostering
a friendly engineering atmosphere. For the last 5 years, he's been
rocking Kotlin for backend projects.