Quarkus at JCon Europe 2026

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Event Description: Dive into the pulsating heart of the Java community at JCON EUROPE 2026, the premier in-person Java community conference in Germany, lovingly organized by the Java User Group Oberpfalz in collaboration with JAVAPRO Magazine.

Date: April 20-23, 2026
Location: Cologne, Germany
Event Type: In-Person

https://2026.europe.jcon.one/

Monday Workshop

Session: Think AI is only for Python? Think again. A hands-on Java AI workshop that will change your mind!
Speaker(s): Don Bourne & Michal Broz
Date/Time: Monday April 20 at Startplatz (a side building next to the Cinedom).
Language: English
Abstract: AI agents aren’t a “Python-only DLC.” In this hands-on workshop, Don Bourne (Software Architect @ IBM) and Michal Broz (Innovation & Incubation @ IBM) show how to build agent-powered Java apps with LangChain4j—from your first working agent to an approach you can responsibly ship. You’ll create and deploy agents that can handle real tasks, then level them up with the right “gear”: tools, resources, and guardrails so they can make useful decisions instead of confidently hallucinating their way into trouble.

You won’t just “make an agent talk.” You’ll learn how to design agents that solve concrete tasks, how to avoid the classic “one mega-agent” anti-pattern that gets slow and expensive, and how to split responsibilities into multiple specialized agents using agentic workflow patterns—so results improve while costs and complexity stay under control. You’ll leave with a working, enterprise-style reference you can adapt at work or in side projects, plus a clear mental model for when agents are actually worth it in Java.

Wednesday Sessions

Session: Local Development in the AI Era
Speaker(s): Kevin Dubois
Date/Time: Wednesday April 22 • 14:30-15:15 at Cinema 7
Abstract: Most of us like to do local development. It means we’re in control of any dependencies, network issues/latency, configurations and cost. And we love to say that “It works on my machine” don’t we? 🙂

Now, with the advent of AI-driven development, it has become more challenging than ever before to do pure local development.

In this session we’ll take a look at various solutions to continue to do local, network-optional development, even with AI:

• How to find and run open source AI models locally.
• Evaluate different (open source) code assistants that can work with these locally running models
• Infuse Agentic AI into our locally running code (including agents, AI client, MCP Servers and using local models)
• Compare models from different vendors; and with different sizes to find the right balance between performance and accuracy
• Weigh pros and cons of using local vs remote models

Come to this session to learn more about local development while leveraging AI to optimize our development flow, code and our functionality itself!

Thursday Sessions

Session: 3 Years of Quarkus in Production, What Have We Learned?
Speaker(s): Jago de Vreede
Date/Time: Thursday April 23 • 09:00-09:45 at Cinema Black Box
Language: English
Abstract: Quarkus has grown in popularity in the last years, but what’s it really like to use it in large-scale, real-world business projects? In this session, we’ll move beyond the basics of "Hello World" to explore how to build enterprise-level applications with Quarkus efficiently.
In this talk we will set up a multi-module project, incorporating integration tests and addressing the challenges with build times, while maintaining a high development velocity. Next, we’ll tackle an upgrade scenario and splitting the application into multiple microservices. Along the way, we’ll share hard-earned lessons, including what to avoid.
At the end of the talk, you should have a good understanding of how to efficiently set up a “big” enterprise project with Quarkus and the confidence to get started.

Session: Building Observable Java Apps that Scale with Quarkus
Speaker(s): Thiago Gonzaga
Date/Time: Thursday April 23 • 11:30-12:15 at Cinema 7
Language: English
Abstract: Observability is not a luxury anymore — it’s a survival skill. In this talk, we’ll go hands-on with Quarkus and OpenTelemetry, demonstrating how to instrument your code to generate traces, metrics, and logs with minimal friction. We’ll wire everything into an LGTM stack (Loki, Grafana, Tempo, Mimir) and see how it all comes together when apps hit production. This session is about solving real developer pain: moving from “it works on my machine” to “I can actually see what’s happening in production.” You’ll leave with practical code examples and a mental model to build observable Java apps that scale with Quarkus and OpenTelemetry.

Session: Serverless Java Web Applications on AWS Lambda with Micronaut, Quarkus and Spring Boot
Speaker(s): Vadym Kazulkin
Date/Time: Thursday April 23 • 14:30-15:15 at Cinema 5
Language: English
Abstract: In this talk, I will present and compare several approaches of how to develop, run and optimize Java web applications on AWS Lambda using Micronaut, Quarkus and Spring Boot frameworks.

I'll also discuss strategies how to reduce the cold start of such Lambda function with AWS Custom Lambda Runtime based on GraalVM Native Image and AWS own offering SnapStart based on Firecracker microVM snapshot and restore and CRaC (Coordinated Restore at Checkpoint) runtime hooks.

I'll into the SnapStart priming techniques which help us increase the Lambda performance and explore how AWS Lambda Profiler for Java can help us identify this potential. We'll also explore the impact of the SnapStart snapshot tiered low-latency cache on the cold start times.

I'll also discuss various optimization strategies to improve the performance (the cold and warm start time) of the Lambda function.

Session: Talk to Your Data: Natural Language Data Access in Java with Hibernate, Quarkus, and LangChain4j
Speaker(s): Marco Belladelli
Date/Time: Thursday April 23 • 14:30-15:15 at Cinema 6
Language: English
Abstract: Explore how Hibernate ORM, Quarkus, and LangChain4j come together to enable natural language interactions with relational data in your Java application. Leveraging Hibernate’s deep understanding of your domain model and data access layer, new tools now bridge the gap between structured information and LLMs, allowing users and agents to query and explore data using plain language.

We'll demonstrate with a live demo of a Quarkus application how to interact in natural language with your existing Hibernate data model, showing both how to manipulate data and how to use them to implement a simple but effective RAG pattern. This style of data interaction can leverage Hibernate’s type-safe mappings, semantic-rich HQL, and fail-fast validation, making data manipulation more effective and reducing hallucinations.

Finally, we will also demonstrate how to easily expose this tool as an MCP server through Quarkus, allowing it to be conveniently consumed by other external agents.