📢 Writing Fearless Tests & Agentic AI in Kotlin

RotterdamJUG is back with two amazing talks:

Wouter Bauweraerts 🇧🇪 will share how to write tests that truly survive refactoring, while David Stibbe 🇳🇱 explores the promise (and pain) of building agentic AI systems with MCP in Kotlin.

🏢 Our host this time: Lunatech

Lunatech is an organization of self-managing developers in small teams. They work on projects for customers, either on site or from one of their offices in Paris or Rotterdam. We’re excited to welcome you high above the city in their 22nd floor Rotterdam office!

🗓️ Schedule 🗓️

17:30 – Doors open, food & drinks available 🍕🥤👋🏼
18:30 – From Fragile to Fearless: Writing Tests That Last (by Wouter Bauweraerts)
19:30 – MCP in Kotlin: Useful, Frustrating, and Weirdly Fun (by David Stibbe)
20:30 – Networking & drinks 🍻
21:30 – Time to head home

From Fragile to Fearless: Writing Tests That Last

How do you write tests that survive refactoring instead of breaking along the way? Wouter dives into two different styles of unit testing, solitary vs sociable, unpacks the definition of a “unit,” and shows how to avoid fragile tests that slow you down. Expect practical code examples, subtle distinctions between unit and integration tests, and strategies to keep your tests useful long after your code has changed.

Wouter Bauweraerts is a skilled Java developer with over seven years at The Beehive. As a full stack developer, he loves solving complex problems and experimenting with new technologies. Beyond coding, he coaches colleagues, has taught programming at Karel de Grote Community College in Antwerp, and brings a strong focus on quality and learning to every project.

MCP in Kotlin: Useful, Frustrating, and Weirdly Fun

Agentic AI and the Multi Context Protocol (MCP) promise smarter, tool-aware AI agents: but what’s hype and what’s real? David cuts through the noise and shows what MCP actually solves (and what it doesn’t). You’ll see how to build both a server and client with the Kotlin SDK, discover caveats from real-world use, and learn where MCP can actually help you today.

David Stibbe has been a full-time, strongly opinionated Java developer since 2008 and discovered the beauty of Kotlin in 2019. In his spare time he hacks on projects ranging from game dev to AI, and loves sharing his learnings at meetups, conferences, and with colleagues on the job.

📍 Location

Lunatech – Spaces Building (22nd floor)
Hofplein 20
3032 AC Rotterdam

Use the back entrance (next to the parking) after 18:00. If the door is locked, call 010 750 2600.

🚉 Public Transport
The office is right at Rotterdam Hofplein, a short walk from Rotterdam Central Station.

🚙 Parking
Paid parking is available nearby in the city center.

🎤 Want to be on stage yourself?
We’re always looking for new (local) speakers and future hosts. Drop us a message or talk to us during the event!