Tue, May 12 · 5:00 PM CEST
We are excited to announce our next Utrecht JUG meetup, on May 12th hosted by JDriven . It will be an evening packed with practical insights and real-world lessons from modern software development. Join us for a great mix of knowledge sharing, engaging talks, and of course food, drinks, and good conversations.
We kick off the evening with food and drinks before diving into our first session, where Susanne Pieterse explores how Retrieval-Augmented Generation (RAG) can be applied in large-scale, real-world environments. Moving beyond demos, she’ll share hands-on experiences from modernizing legacy systems, covering challenges like document processing, access control, and keeping AI grounded in reliable data.
After the break, Jos Roseboom takes the stage with a deep dive into performance pitfalls in JPA and related technologies. With practical examples and a touch of humor, this session uncovers how ORM abstractions can sometimes lead to unexpected slowdowns and how to detect and fix them before they impact your users.
We’ll wrap up the evening with drinks, giving you plenty of time to connect with fellow developers, exchange ideas, and reflect on the sessions. Plus, don’t miss the chance to win a JetBrains license in our giveaway.
Join us for an evening full of learning, inspiration, and great conversations.
Please join us and RSVP!
Because of the limited number of seats, please keep your RSVP up-to-date, so we can welcome someone else if you can't make it.
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## Timeschedule
17:00 Doors open
# Giveaway
1 JetBrains licence
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# Talks
## RAG in the Wild: Real-World Lessons from Modernizing Legacy Systems
Enterprise and government document systems hold terabytes of valuable unstructured information, yet most still rely on keyword and metadata search with little semantic context. Retrieval-Augmented Generation (RAG) promises a breakthrough, but tutorials rarely prepare you for regulated, large-scale environments.
In this talk, I’ll share lessons from building a RAG stack with Spring Boot, Elasticsearch, LangChain4j, Docker, and ActiveMQ, using both Azure OpenAI and Ollama. Expect concrete insights on document chunking, enforcing access control, and keeping LLMs grounded in facts — practical takeaways for anyone bringing RAG from demo to production.
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# When ORM Becomes OMG: Performance Pitfalls in JPA and Friends
JPA makes database interaction feel almost magical—until your app grinds to a halt. In this talk, we’ll take a tour through the common (and not-so-common) performance pitfalls that turn object-relational mapping into an object-relational mess. From data loading surprises to connection mismanagement, we’ll explore real-world issues using a sample app: the FunFactStore, where fun facts are sold, but bugs are free.
We’ll dig into how seemingly harmless libraries can sometimes do more harm than good, and how tooling can help you spot trouble before your users do. Whether you’re using Spring Data JPA, navigating tricky transaction boundaries, or just wondering why things suddenly got slow, this session offers practical insights—and maybe a few fun facts.
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# Speakers
## Susanne Pieterse
As an autodidact full-stack engineer and iSAQB-certified software architect, Susanne thrives on innovation, learning, and knowledge-sharing, with tea and a heavy-bag boxing workout fueling the journey. She helps Java developers, who are eager to explore generative AI, transform their ideas into high-value, real-world creations.
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## Jos Roseboom
Jos gets a smile on his face when he makes other people happy by letting a computer do what they don’t like to do. He has been trying to do so professionally for the past 16 years. In his spare time, Jos likes to play tennis. He is a trainer/coach for kids playing the typical Dutch sport korfball.
