Amsterdam JUG Meetup at Software Improvement Group (SIG)

Celebrating and preparing for the very first Voxxed Days Amsterdam taking place next day, April 3, join in with the latest Amsterdam JUG Meetup at Software Improvement Group, Fred. Roeskestraat 115, 1076 EE Amsterdam.

**It's possible to park at the location for free (after all), please send your license plate number to amsterdamjug@googlegroups.com.**

For more details and discussions on the below, go to bit.ly/join-foojay-slack to join the Friends of OpenJDK (Foojay.io) Slack and use the #jug-amsterdam channel for conversations related to the below.

In this meetup, in addition to food, drinks, and networking, you will experience four excellent talks of approximately 30 minutes each:

18:00 - Doors Open (And Food!)
19:00 - 19:30 Talk 1: Bruno Oliveira, Senior Software Developer at Software Improvement Group—"Engineering RAG: Efficiently Transforming 25 Years Worth of Documents into Readily Available Insights"
19:30 - 20:00 Talk 2: Peter Schuler, Senior Java Developer and Community Lead at Rabobank—"Test Driven Development: This Is The Way"
20:00 Short Break
20:15 - 20:45 Talk 3: Martijn van Iersel, Senior Developer at TOPdesk—"Lessons from a Month of Internationalization Puzzles"
20:45 - 21:15 Talk 4: Christian Tzolov, Spring AI Lead at Broadcom—"Beyond Basic LLMs: Building Agentic Systems with MCP and Spring AI"
21:15 - Networking drinks

Abstracts

Engineering RAG: Efficiently transforming 25 years’ worth of documents into readily available Insights—Bruno Oliveira, Senior Software Developer at Software Improvement Group

We'll explore Software Improvement Group’s development of a Retrieval-Augmented Generation (RAG) system, designed to unlock insights from 25 years of software consultancy documents.

You'll learn about key engineering challenges and solutions in scaling document processing, optimizing vector storage, and implementing metadata handling, using open-source technologies.

Attendees will gain practical insights for initiating or optimizing RAG projects, based on our experience in transforming extensive software engineering knowledge into an accessible, intelligent resource.

Test Driven Development: This Is The Way—Peter Schuler, Senior Java Developer and Community Lead at Rabobank

We all know that applications should be tested before going to production. All coders know that code should be covered with unit tests. But the best approach is to write unit tests before you write the actual code.

This talk will show you why Test Driven Development is a superior approach to writing unit tests, and developing software in general. Also, you will see ways to make writing unit tests fun and how to use them to gain a better understanding of the business problems you are solving.

The journey might start off slow but very soon you will find yourself moving ludicrously fast and you will see that This Is The Way.

Lessons from a Month of Internationalization Puzzles—Martijn van Iersel, Senior Developer at TOPdesk

Encodings. Time Zones. Accented Characters. Daylight savings time. Do these words make you feel dread and anxiety? Amongst programmers, these topics are notorious for being the source of subtle, tricky bugs. Yet knowledge in this area is vital. To make learning this topic fresh & exciting, I created i18n-puzzles.com, inspired by the famous Advent of Code. After all, which programmer can resist a good puzzle?

Originally designed as an internal training, i18n-puzzles.com has now become a public community event. In March 2025, I published new puzzles almost every day. Now the time has come to look back.

What was the most challenging puzzle? What was the most interesting solution? What are common pitfalls? If we compare different programming languages, which one handles internationalization in the most elegant way? What can we learn from each puzzle?

Beyond Basic LLMs: Building Agentic Systems with MCP and Spring AI—Christian Tzolov, Spring AI Lead at Broadcom

As Large Language Models evolve, developers face new challenges evolving from simple prompt-response patterns to building sophisticated AI agents capable of real-world system interactions.

This presentation explores the architectural challanges in developing practical AI agents using the Model Context Protocol (MCP) and Spring AI frameworks.

We'll examine the spectrum from deterministic Workflow approaches to autonomous Agent architectures, highlighting when each strategy provides optimal value.

Through hands-on demonstrations, you'll discover how Spring AI's integration capabilities combined with MCP's standardized interfaces dramatically reduce the complexity of building production-ready AI applications.