Software Engineering Events in Utrecht

Full-stack meetup in Utrecht, Netherlands

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.

17:00 Doors open
17:45 Food & Drinks
18:30 RAG in the Wild: Real-World Lessons from Modernizing Legacy Systems by Susanne Pieterse
19:30 Break
19:45 When ORM Becomes OMG: Performance Pitfalls in JPA and Friends by Jos Roseboom
20:45 Drinks

1 JetBrains licence

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.

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.

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.

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.

Lets go!

Edition 1 of the Coding Dojo in Utrecht!
Kata will be announced later, but this will be a fun one..

Please RSVP so we can order enough pizzas 🍕

18:00 - 21:00 hours, walk-in from 17:30
Drift 17, Utrecht (bus stop Janskerkhof)

Do you want to meet fellow Women in Rust at RustWeek 2026? Join our friendly and vibrant community for lunch on Tuesday 19 May at 12.45pm CEST. Find us at a dedicated table in the lunch area!

This will be an opportunity to share experiences, expand your network, and simply enjoy a chat with like-minded individuals.

Please note that a RustWeek 2026 ticket is required to enter the venue. More info at https://2026.rustweek.org.

Welkom bij Coding Wednesday!
Samen duiken we in de creatieve wereld van programmeren. Elke maand is er een challenge of workshop gericht op coderen. In de regel maken we gebruik van de programmeertalen die je bij Novi leert (Python, Javascript, Java)

Wat doen we deze keer?
Altijd al samen willen werken aan een programmeerproject? Deze Coding Wednesday bouwen we een website na met de hele groep. Iedereen krijgt een apart onderdeel om te designen. Dit doen we met HTML, CSS en het Javascript framework React. De onderdelen worden met pull requests samengevoegd in het Github project.

Heb ik voorkennis nodig?
Het is handig als je al wat programmeerervaring hebt en hebt gewerkt met Github. Zo niet, kijk vooral mee om iets op te steken. Of werk met iemand samen!
Uiteraard kan je je voorbereiden met online tutorials.

Wat heb je nodig?

• Je eigen laptop met WiFi aansluiting
• Installeer een code editor. Novi studenten kunnen Webstorm of IntelliJ gebruiken. Anders is VSCode een prima editor
• Zorg dat je een Github account hebt en Git hebt geinstalleerd. Tip: oefen vooraf met een dummy project om te zien of je code kan toevoegen vanaf een pull request.

Is er een minimum aantal aanmeldingen?
Coding Wednesday gaat door als er 5 aanmeldingen zijn of meer. Dus vergeet vooral niet om je aan te melden :)
Mocht het niet doorgaan, laten we dit hier weten voor 13 mei 12:00 uur!

Details:
📅 Wanneer: Woensdag 13 mei 2026, 14:00 uur (tot uiterlijk 17:00)
📍 Waar: Op locatie! Newtonlaan 247, Utrecht (4e etage)

De Test Automation Days 2026 zijn net een maand voorbij, maar wij zijn er nog niet klaar mee. Tijd voor de aftermatch, maar dan op onze eigen manier. Zoals altijd georganiseerd door deTesters, TestCoders en TechChamps, in ons kantoor in de Werkspoorkathedraal in Utrecht.

Deze keer halen we twee Test Automation Days talks naar Utrecht die mooi laten zien hoe breed en interessant ons vakgebied inmiddels is.

Met Remco Ridder, van ons zusterbedrijf Squerist, en Anaïs van Asselt, oud collega van deTesters en nog altijd een vriendin van de show, belooft dit weer een avond te worden vol praktijkverhalen, nieuwe inzichten en genoeg om over na te praten.
Het zijn twee talks, twee verschillende invalshoeken, maar allebei heel relevant voor iedereen die serieus bezig is met kwaliteit, test automation en hoe we slimmer kunnen werken.

Performance Testing as a Pipeline Essential
Performance testing. We weten allemaal dat het belangrijk is, maar toch gebeurt het in veel teams nog niet, te weinig of alleen vlak voor productie. En precies daar ontstaat risico. Zeker in omgevingen waar snel en vaak gedeployed wordt, wil je niet pas weken later ontdekken dat de performance ondertussen achteruit is gegaan.
In deze sessie laat Remco zien hoe je die kloof kunt verkleinen door performance testing een vast onderdeel te maken van je software delivery pipeline. Niet als losse activiteit achteraf, maar als een automatische stap in je delivery proces. Zo kun je performance regressies binnen minuten signaleren in plaats van pas veel later.
Kortom, een sessie voor iedereen die performance testing belangrijk vindt, maar het nog niet structureel heeft ingebed in zijn/haar manier van werken.

Remco Ridder
Remco is Test Automation Engineer bij Squerist, ons zusterbedrijf. Hij houdt zich bezig met kwaliteit in de volle breedte en laat in deze sessie zien hoe performance testing praktischer, sneller en vooral waardevoller kan worden als je het op de juiste plek in je proces opneemt.

Feedback as Fertiliser: From Sh*t to Quality Through AI and Knowledge Automation
Veel waardevolle feedback verdwijnt sneller dan we zouden willen. Bugs worden gesloten, incidenten raken vergeten en productvragen verdwijnen in losse tools of gesprekken. Zonde, want juist in al die informatie zit een schat aan kennis die kan helpen om kwaliteit structureel te verbeteren.
In deze sessie laat Anaïs zien hoe je met AI, RAG en low code automation van al die losse signalen iets bruikbaars kunt maken. Denk aan een levende kennisbank, slimmere inzichten in risico’s en een betere manier om QA inspanningen te prioriteren. Niet door nóg meer handmatig werk toe te voegen, maar juist door feedback slimmer te organiseren en opnieuw te gebruiken.
Een verhaal dat laat zien hoe je van ruis weer richting kunt maken, en hoe een duurzaam QA ecosysteem zichzelf steeds verder kan verbeteren op basis van wat er al gebeurt.

Anaïs van Asselt
Anaïs is Senior QA bij Choco. Voor veel mensen in onze community is zij geen onbekende naam, vooral omdat zij een graag geziene spreker op diverse Test (Automation) conferenties. Ze werkte eerder bij deTesters en is sindsdien eigenlijk nooit echt weggeweest. Anaïs staat bekend om haar praktische blik op kwaliteit en haar talent om technologie, automatisering en teamdynamiek slim bij elkaar te brengen.

Doelgroep
Deze meetup is interessant voor testers, QA engineers, developers en iedereen die bezig is met kwaliteit in moderne software teams.
Deze avond is volledig in het Nederlands (Dutch spoken).

Programma
17:30 Ontvangst en eten
18:30 Performance Testing as a Pipeline Essential
19:30 Korte pauze
19:45 Feedback as Fertiliser: From Sh*t to Quality Through AI and Knowledge Automation
20:30 Q&A en discussie
21:00 Afsluiting met een borrel

We’re excited to welcome everyone attending RustWeek 2026 for another collaborative day of coding!

This year, we’re partnering up with Zed and Kiesraad (Dutch Electoral Council) to bring you some fun challenges to hack on.

The Electoral Council’s Abacus engineers will be on-site to collaborate with you on software for election results and seat allocation, with several good first issues and challenges, and they would love your input and proof-of-concept ideas!

You do not need a ticket to the RustWeek conference to attend the hackathon. The hackathon is free of charge; we will provide coffee, tea, lunch and refreshments.

The hackathon will be held at Kinepolis, the same venue as the conference.

Schedule
Doors open: 9:00
Opening: 9.30
Lunch: 13:30
Wrapping up: 17.30

Looking for more fun things to do during RustWeek? Take a look at our activities page: https://2026.rustweek.org/events/social-activities/.

In a world where new frameworks, tools, and trends seem to appear every week, it’s easy to forget where true technical strength and innovation come from: the fundamentals.

At Back to the Future of Code, we invite developers to explore the foundational building blocks behind modern software. Three speakers will each offer a different perspective on these fundamentals and highlight why they’re still at the heart of great engineering.

Talks:
🎤 Frontend Framework Dependency: Are we skipping the hard part → Ramona Domen (Software Engineer and Impact Leader)
Ramona shows how modern frontend frameworks still depend on HTML, CSS, and JavaScript. And why mastering these foundations makes you a more deliberate and powerful engineer.

🎤 Why Great Engineers Don’t Just Write Code → Sarah Gruneisen (Engineering Leader & Leadership Coach )
Sarah’s talk highlights how many engineers, especially women, have their strategic and technical strengths overlooked in favor of their “people skills”. She reveals how those very skills drive real technical impact and invites us to broaden our definition of engineering excellence.

🎤 Women in Tech: Bug or Feature? → Maaike Wachters (Software Engineer)
Maaike uncovers the hidden history of female tech pioneers whose groundbreaking ideas laid the foundation for the way we code and innovate today.

Program

• 17:15 – 18:00 Walk in and dinner (vegetarian options)
• 18:00 Intro WeCode and KVK
• 18:20 Talks and Q&A (in English)
• 20:00 – 21:00 Snacks and drinks

Who should attend?
This event is especially designed to spotlight and elevate women’s voices in tech by giving them a place on the stage. Everyone is welcome to join.

How to get there
KVK is located at Sint Jacobsstraat 300, 3511BT Utrecht. (KVK has two buildings on the same street, so look out for number 300)

• By car: Paid parking is available at Q-Park La Vie or Paardenveld.
• By train: The nearest train station is Utrecht Centraal, about a 10-minute walk.
• By bus: Take lines 1, 3, 6, 7 or 27 to bus stop Sint Jacobsstraat.
• By bike: There are bike racks available close to the location.

You need to bring identification because we're in a goverment building. (ID-card, drivers license, passport).

Change of plans?
Please cancel your RSVP so someone on the waiting list can take your spot. Thank you!

Photography
We will be taking photos during the event to capture the atmosphere and share highlights afterward online. If you’d rather not be photographed, let our team know.

Questions
If you have any questions or need special accommodations, please contact us at wecode@kvk.nl.

Join us at the Valcon Meetup in Utrecht .

Schedule
17:45 - 18:45 - Walk in, networking and dinner
18:45 - 19:20 - Part 1: Bridging a gap at DISA
19:20 - 19:30 - Short break
19:30 - 20:00 - Part 2: Mendix Mystery
20:00 - 21:00 - Drinks and networking

Part 1: Bridging a gap at DISA
DISA was founded to bridge a gap. A gap in one of the most critical processes in the Netherlands: identifying and screening every asylum seeker entering the country. They started from zero, with nothing but paper forms and urgency. That paper process needed to become digital, fast. That's where Mendix came in. But how do you turn something so unpredictable into a reliable workflow application? Every asylum seeker brings a different story, different documents, and different needs. The workflow needed guardrails, but also freedom.
Add to that a UX challenge: newly hired staff, many with limited computer experience, had to use this every single day. And behind the scenes, integrating with the national immigration partner chain, each with their own systems, on-premise, across multiple servers, turned every connection into a technical puzzle.
Come hear how we built a Mendix application that is structured enough to be trusted, flexible enough to be useful, and simple enough for anyone to use.

Part 2: Mendix Mystery
You've been building in Mendix.... But have you ever stopped to wonder — are you really using it to its full potential? There's a concept most developers walk past every single day. Simple on the surface. Powerful underneath. Once it clicks, you'll never build the same way again

Dinner
Two diner options are being served from 17:45 - 18:45h. Both options are also available as vegetarian options.

Parking
The Valcon office is situated at Leidsche Rijn central area. It is a short walk from train station Utrecht Leidsche Rijn. If coming by car there are ample parking spots available in the parking garage below the Jumbo foodmarket.

Entrance
Please enter the Valcon office from street level, not from the parking garage. A clear meetup banner and host will be there to register and welcome you into our office.

About Mendix Meetups
The Mendix Community Meetups are about meeting other makers, knowledge sharing, and learning something new.
The content of the meetups are not about:

• Sales
• Marketing
• Recruitment

To learn more about the meetups or if you want to organize your own meetup, contact the Community Team at community at Mendix dot com.

We'll start into the weekend with some Sport and what is better than having a bike tour on Friday 22nd May? If you'd like to bike along, sign up here! We expect this to take about 4 to 5 hours.

On the route, we will see at least two beautiful castles, and we’ll have a pause in Breukelen where we will get a snack!

This tour is for everyone. You don't have to prepare anything, it's enough to be at the bike rental at the time.

The following information is for the curious: You can see the tour on the app Komoot. It's approx. 46km, we may adapt it as a group on the day. As last year we’re very flexible and adaptive!

The bike rental is payed by Stichting Rust Nederland. Many thanks to Erik Jonkers for the sponsoring and to Jana Dönszelman for helping with the meetup page and organization.

Agenda

1. We'll meet at the bike rental place it is near to the conference venue. (5 Minutes by bike)
2. Everyone receives their bike.
3. We’ll go over “Hogeweidebrücke”
4. We’ll see Kasteel Nijenrode and get a snack at the marketplace of Breukelen
5. We’ll see Schloss Zuylen
6. We ride back to Utrecht and return the bikes!

Looking for more fun things to do during RustWeek? Take a look at our activities page: https://2026.rustweek.org/events/social-activities/

Mark your calendars: the next Haskell Utrecht Meetup will be on June 1st! This time, we will be generously hosted by Chordify's in their office, Burgemeester Reigerstraat 89.

We hope to see you there!

Agenda:

• 19:00 Doors open
• 19:30 Welcome
• 19:35 Hugo Peters - Making people secretly use an Haskell EDSL
• Break
• 20:30 Matteo Bertorotta - Compilation techniques using Fusion in Haskell
• 21:00-ish Wrap up

Hugo Peters (NVIDIA) - Making people secretly use an Haskell EDSL

In this talk, I'll show how we use the bluefin effect system to design simple but effective DSL builders for non-Haskell programmers.

Matteo Bertorotta (Utrecht University) - Compilation techniques using Fusion in Haskell

We discuss fusion as a powerful mechanic for optimization during compilation, specifically focusing on how fusion techniques eliminate intermediate data structures to maximize runtime efficiency. We explore two similar examples in vastly different domains: (1) Transforming elegant library code into a performant counterpart, and (2) fusing complex gradient computations in reverse automatic differentiation into a single pass.

Spots are limited: https://tickets.voxxeddays.com/event/workshop-victor-rentea

Build faster, smarter software with AI.
Join an exclusive, fully catered workshop with Victor Rentea on Agentic Engineering in a small, focused group of engineers.

Upgrade your development workflow to 2026.
A hands-on day on AI Coding Agents: prompt & context engineering, multi-agent orchestration, spec-driven development, and self-improving skills.
Learn how engineers reach 2x–10x productivity and what it takes to get there.

For: all engineers (backend, frontend, QA, data, ops)
Bring: laptop with Claude Code + subscription (Pro is enough)
The agenda of the day
Introduction

• LLM Fundamentals: Predictions, Tokens, Context Window, Compaction, System Prompt, Model vs Agent Harness
• AI Pitfalls: Sycophancy, Hallucinations, Attention Dilution, Knowledge Cutoff, Premature Fixation
• MCP Tools – best-of

Context Engineering

• Evolving a Token-Efficient Project Memory
• AI Context Sharing across repos, teams, and company
• Skills and Custom Agents that self-improve
• Token-Efficiency Tricks: context hygiene, DRY, grep-logs antipattern

Prompt Engineering & Orchestration

• Prompt Engineering – does and dont’s
• Brainstorm, plan & generate a non-trivial change with AI
• Multi-Agent Orchestration Patterns: handover, reviewer, orchestrator, advisor,…

AI Guardrails & Security

• Functional Guardrails with State-of-the-art Acceptance Tests
• ⁠Code Quality Guardrails AI cannot circumvent
• ⁠Architecture Guardrails & Exact Summarisation
• APIs, C4 Model, sequence diagrams
• AI Supply-Chain Attacks Attacks and Agent Isolation Techniques

Date: Wednesday, July 1st (09:00 - 17:00)
Location: Utrecht (venue TBA)
Price: € 395,- (incl. lunch & drinks)

Spots are limited: https://tickets.voxxeddays.com/event/workshop-victor-rentea