Java Concurrency

Parking: Please use public transport if possible. If arriving by car, use a P+R or park at the Jaarbeurs parking (paid). Public Transit: 5 minute walk from Utrecht Central station **Event Schedule** **17:00** — Doors open & walk-in **17:30** — Dinner **18:30** — Welcome *Atanas Aleksiev — Rabobank Engineering Services AWS team* **18:35 -** Disasters don’t announce themselves—and recovery is only as good as your last backup strategy *Rabobank Engineering Services AWS team* **19:10 -** From Innovation to Enterprise: Scaling a Compliant, Microservices-Driven AWS Platform *Rabobank ODP Next team* **19:50** \- Break ☕ **20:00 -** EDSN as the Digital Backbone of the Energy Market: Use Case, Technology Choices and Challenges *Energie Data Services Nederland* **20:40** \- Drinks & Networking 🍻 **21:30** -Event ends **Summary of the talks** **Talk 1:** In this talk, we’ll walk through how Rabobank designs for failure using AWS Backup: from automated policies and immutable vaults to restore testing and ransomware protection. Because resilience isn’t just about having backups—it’s about knowing they work. **Talk 2:** What happens after an innovation delivers a promising platform before it’s ready for enterprise scale, governance, and speed? That’s where our journey begins. You’ll hear how we evolved the architecture to support over 100 microservices powering digital lending on a compliant-by-design AWS environment. We’ll share the decisions we made along the way: what we kept and what we changed. Central to our approach is Infrastructure as Code to enable consistency, repeatability, and control on the platform. We’ll show how this foundation helped us automate operations, accelerate delivery, and meet strict compliance requirements. Join us to learn how to bridge the gap between innovation and enterprise readiness, turning a promising start into a scalable, secure, and developer-friendly platform. **Talk 3:** EDSN acts as the digital backbone of the energy market, supporting essential data exchange processes across the energy market value chain. We explore this role, the underlying IT foundation, and the challenges and trade-offs that come with it.

Tijdens de maakavonden van Meet Je Stad soldeer je je eigen meetkastje dat temperatuur, luchtvochtigheid en fijnstof\* kan meten. Het solderen is geschikt voor iedereen: van beginner tot expert! Daarnaast bieden we begeleiding, dus hoef je niet bang te zijn dat je er niet uit komt. Ter deelname betaal je €15 voor de materialen. Vaak lukt het niet om al het soldeerwerk binnen één avond af te krijgen, maar dit is geen probleem; tijdens onze volgende maakavonden kun je langskomen om je werk af te maken. Inmiddels zijn er in de stad Utrecht nu zo’n 150 mensen die hun eigen meetkastje hebben gesoldeerd. Als je kastje af is wordt hij geregistreerd en kun je hem bij jou thuis ophangen/neerzetten. Hierbij krijg je instructies zodat je de juiste locatie kunt kiezen en je metingen zo betrouwbaar mogelijk zijn. Als het dan eenmaal hangt kun je via de kaart op de [website van Meet Je Stad](https://meetjestad.net/index3.php?loc=Tb) bijhouden welke metingen je kastje neemt: zo kun je bijvoorbeeld zien op welke momenten het bij jou het warmst is en vergelijkingen maken met waardes van andere meetkastjes. Dat kan door middel van [deze tool](https://mjs-datavisualisation-fez7kynngq-ez.a.run.app/) die je helpt om grafieken te maken. Dan kan je er achter komen hoe jouw omgeving ervoor staat in vergelijking met de rest van de stad. Meet Je Stad organiseert ook kennisavonden met gastsprekers die vertellen over hitte, fijnstof en andere burgerinitiatieven in de stad. Dit zijn ook gelijk geschikte momenten voor deelnemers om met elkaar in discussie te gaan over hun metingen en ondervindingen. Zo hopen we een netwerk van betrokken inwoners te creëren en meer te weten te komen over de milieuomstandigheden in de stad! *\*De fijnstofsensor is optioneel en kost 20 euro extra. Indien je deze bij je meetkastje wilt moet je deze via een draad met een stroombron binnen 15 meter kunnen verbinden.* **Organisatie:** Milieucentrum Utrecht (MCU) in samenwerking met de Makerscommunity HaHaHo. **Locatie:** Bibliotheek Neude, Huis van Actief Burgerschap (begane grond) **Kosten:** 15 euro voor materiaalkosten, 20 euro extra voor fijnstofsensor. (Meet-up suggereert bij het aanmaken van een account dat een betaald abonnement vereist is. Dit is niet zo, op de pagina waar gevraagd wordt om een abonnement te kiezen staat rechts bovenin de optie "Ga door met het gratis plan".) *Bij te weinig aanmeldingen kan de workshop afgelast worden.*

Time for our biweekly peer Satsang gathering! This is an open, equal and low-key gathering for spiritual seekers from all walks of life to get together, talk, feel connected and grow. The gathering will last for about two hours. Bring questions, thoughts, or just your presence. We'll see what unfolds once we're there. If you're interested but can't make the currently indicated time, the event is full or you have any other questions, get in touch with me at thijshugenholtz@gmail.com and we'll see what we can do! Location: Buurtcentrum Hart van Noord, Trumanlaan 60 Utrecht but the entrance is opposite Geallieerdenlaan 24

If you are living in The Netherlands, by now, you may well have noticed the amount of open water. If you enjoy cycling in the city, you may wish to feel safer as you navigate the bridges and canals. And you may also want to get ready for visiting the beach, pools or the many lakes this summer. Learning how to swim takes approx 1 year and it all starts with the very first lesson. New comers enroll via our website and pay € 30,50, this is the first lesson and a goody bag. After the class you agree with the personal swim coach how to continue to obtain your final objectives. Enrolling is only possible via [www.your-personal-swim-coach.nl ](https://www.your-personal-swim-coach.nl/)hence a rvsp via meetup is not enough.

A great ride along the Vecht and Gein rivers. You will love this route. Please ride single file along the winding river as there can be cars around each corner. **Route:** https://connect.garmin.com/modern/course/441606271 GPX: https://drive.google.com/file/d/17-T_pT_GH3QKSFcH1WWgfArvxSdAkVzO/view?usp=sharing **Afterwards:** Drinks at Polder https://maps.app.goo.gl/tbt5DDG7YLU3uWvaA **Rules:** \- Download the route to your cycling computer so you can always find your way home \- Make sure to arrive on time \- Before you ride\, decide as a group how you want to ride: you can split up in a fast and a slow group or stay together\, but make sure to discuss what pace you are going to ride and whether you are going to wait if someone is slower than the group\, or not\.

Samen sporten, gewoon voor de fun, elke week een divers programma, met allerlei verschillende sporten. Je hoeft niet de beste te zijn, maar wel zin hebben om samen te spelen en te leren. Tijdens een training doen we verschillende spelletjes, basketbal, voetbal. volleybal, spikebal, honkbal. Kom je ook, de bal ligt bij jou!! Eerste keer meedoen is altijd gratis, daarna kan je beslissen of dit voor jou is, of niet!! Dus kom een keer proberen. Kan je niet op deze dag, we sporten ook op andere dagen nl Zondag om 9:30 of Maandag om 20:30 Stuur mij een berichtje als je op die dagen een keer wil proberen! The amount of people rsvp'd to this game doesn't match the real number of people at the event, as Meetup is only used for promotion purposes.

***Start your week right, with inner silence and good vibes.*** Join us every week on Monday at the Manenburgstraat 22, for an evening of meditation. No matter if you are an experienced practitioner or an absolute beginner. We are looking to come together, share knowledge about the Sahaja Yoga and enjoy an evening meditation. Our volunteers will be happy to receive you and offer the class for free! Every week will cover a different topic and guided meditation. Let us know if it is your first time when you arrive & we’ll give you a small introduction. Join online or in person by [signing up to our email list](https://8866df56.sibforms.com/v2/serve/MUIFAHMFeBQ-JU5ZLIHgG_4wGm5mFh0wgkKykf7NP-cTZ3gvp-Q_ZKgxUufmfFbV6GHkW5xubkLxVPeOpJTeziqZ90UPck6c7GUbJAHY2X4a6T58Ufps02z55bVxax37If0gPFwwx9PCyRvaFKivyOE7aSAxpM_f7w0j2zwC_PNQyW8rVXIPwUBP6lR9Mn-bET_9P4XQHkSzYAMV). (Fyi: this is not a physical yoga class, no specific attire needed.)

De *veertigste* monthly meetup van [Nimma.codes](https://www.nimma.codes/) alweer! We zijn een cross-language user group voor software developers in de regio Arnhem-Nijmegen en komen elke laatste dinsdag van de maand samen om te praten over alles wat met software development te maken heeft. Wees welkom! (ook als je niet programmeert) *Ditmaal zijn we wederom te gast bij Deftpower [Clean Tech Park Arnhem](https://cleantechparkarnhem.nl/).* **Programma** * **17:30 – 18:00** Inloop + food & drinks * **18:00 – 18:45** Talk 1: [Tim Steenvoorden](https://github.com/timjs) \- De lambda calculus in moderne programmeertalen * **18:45– 19:00** Pauze * **19:00 – 19:45** Talk 2: [Deftpower](https://www.deftpower.com/) - [William van der Vegt](https://vegt.dev/) \- Van thuislaadpaal naar actor: kennismaken met schaalbaar sessiebeheer in \.NET Orleans * **20:00 - 21:00** Netwerken **Talk 1: Tim Steenvoorden (Open Universiteit en Radboud Universiteit) - De lambda calculus in moderne programmeertalen** Eén herschrijfregel, geen types, geen geheugen, geen loops. In 1936 definieerde Alonzo Church een rekenmodel van bijna irritante eenvoud die toch even krachtig is als een Turingmachine: de lambda calculus. Deze sessie is een reis van die wiskundige kern naar de code die je dagelijks schrijft. We beginnen met pen en papier: lambda termen lezen, schrijven en reduceren. We gebruiken niets anders dan functies voor het bouwen van datastructuren. Vervolgens maken we de vertaalslag naar closures, higher-order functions, immutability en pipelines in talen als Java(Script), Python, Kotlin, Haskell en Rust. Het doel is niet om morgen anders te programmeren. Het doel is om te begrijpen waarom moderne talen de afgelopen decennia steeds meer functionele concepten hebben overgenomen en wat de gemeenschappelijke wortel daarvan is. **Talk 2: Deftpower - William van der Vegt - Van thuislaadpaal naar actor: kennismaken met schaalbaar sessiebeheer in .NET Orleans** Ik ben van kleins af aan een echte techfanaat; thuis hobby ik met gadgets, servers en frameworks. Sinds een klein half jaar werk ik bij Deftpower, waar bedrijf, sector én techstack perfect bij me passen. Daarvoor vijf jaar bij Info Support, vooral voor de klanten Air Miles en Moba. Vanuit die liefde voor tech vertel ik wat over .NET Orleans: het framework waarmee we bij Deftpower duizenden thuislaadpalen tegelijk beheren. Duizenden live, stateful verbindingen, elk met hun eigen sessie en toestand. In klassiek .NET loop je dan al snel tegen locks en race conditions aan. In deze talk laat ik zien hoe we elke laadpaal als een actor modelleren met .NET Orleans, en zo schaalbaar bouwen zonder grote concurrency issues. Inclusief een praktische kennismaking met het actor-model, voorkennis van Orleans is niet nodig. **Locatie** [Clean Tech Park Arnhem - Connector gebouw KB - 1ste verdieping.](https://maps.app.goo.gl/VcFWRSbF5fT6J2PB7)

Codelab and the [Rabobank Tech Community](https://www.meetup.com/rabobank-tech-community/) are organising a Java meetup with Victor Rentea about: Agentic Engineering - Patterns and Anti-Patterns If you would like to join, subscribe quickly here (seats are limited): https://www.meetup.com/rabobank-tech-community/events/315294956 === **Agenda** 17:00 Walk in + Dinner 18:15 Talk 20:00 Drinks 21:00 Ending **Talk description** A compilation of emerging patterns and common pitfalls observed in over 50 companies. From unhealthy context management, naive prompting, unvetted AI slop, and careless supply-chain to self-learning skills, sub-agent orchestration, AI guardrails, and backpressure. Join this talk to cut through the hype, learn from the early adopters of agentic engineering – see what works, what ships better code 3x faster in production, and what fails **Speaker** Victor Rentea is a Java Champion and an Independent Trainer delivering intense webinars for dozens of companies worldwide since 2014. His passion is Simple Design, Refactoring, and Unit Testing, about which he regularly talks at top conferences, but also to the European Software Crafters Community that he founded. On victorrentea.ro you can find his blog, best talks, training curriculum, live masterclasses, and social channels.

The Rabobank Tech Community together with [CodeLab](https://www.meetup.com/codelabjug/) is organizing a Java meetup for our community. Victor Rentea will speak at Rabobank in the evening of July 2nd. 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. **IMPORTANT:** Due to Rabobank security measures, we need to present in advance an attendee list with everyone’s full names. This is partly because Rabobank is, well, a bank, but also related to safety measures in case of an emergency. That is why we need to ask you the following: If you do not use your real full name as profile name at Meetup.com, could you send us your full name in a private message? The attendee list presented to Rabobank will only be used for visitor's registration at the reception and will not be published anywhere, we only do this to comply with said safety measures. The meet-up will be held in a non-public area of the building. This means that without proper registration the security team will not be able to let you in. Hoping for your understanding. === **Agenda** 17:00 Walk in + Dinner 18:15 Talk 20:00 Drinks 21:00 Ending **Talk** **Agentic Engineering - Patterns and Anti-Patterns** A compilation of emerging patterns and common pitfalls observed in over 50 companies. From unhealthy context management, naive prompting, unvetted AI slop, and careless supply-chain to self-learning skills, sub-agent orchestration, AI guardrails, and backpressure. Join this talk to cut through the hype, learn from the early adopters of agentic engineering – see what works, what ships better code 3x faster in production, and what fails **Speaker** Victor Rentea is a Java Champion and an Independent Trainer delivering intense webinars for dozens of companies worldwide since 2014. His passion is Simple Design, Refactoring, and Unit Testing, about which he regularly talks at top conferences, but also to the European Software Crafters Community that he founded. On [victorrentea.ro](http://victorrentea.ro/) you can find his blog, best talks, training curriculum, live masterclasses, and social channels.

'THE SYMPATHIZER' by Viet Thanh Nguyen 'The winner of the 2016 Pulitzer Prize for Fiction, as well as seven other awards, The Sympathizer is the breakthrough novel of the year. With the pace and suspense of a thriller and prose that has been compared to Graham Greene and Saul Bellow, The Sympathizer is a sweeping epic of love and betrayal. The narrator, a communist double agent, is a man of two minds, a half-French, half-Vietnamese army captain who arranges to come to America after the Fall of Saigon, and while building a new life with other Vietnamese refugees in Los Angeles is secretly reporting back to his communist superiors in Vietnam. The Sympathizer is a blistering exploration of identity and America, a gripping espionage novel, and a powerful story of love and friendship.' ***Please read the book and join us for a lively discussion (in English) about the contents during our afternoon book club meeting.*** \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\- **PLEASE NOTE:** This is an IN-PERSON event in Amersfoort, The Netherlands. Please cancel your attendance in advance if you are unable to join, so that those on the waitlist can participate. Looking forward to seeing you all IN REAL LIFE then! Best regards, Sandra

We’ve all had it: going blank mid-sentence, a tight chest before a hard conversation, or that strange emptiness right after finally getting what we wanted. This first gathering is a chance to slow down and actually listen to what your body’s been holding. For this session, we’ll explore the question together: what is your body trying to tell you? Through a short opening round, gentle orientation, and guided somatic practice, you’ll get a real feel for what Somatic Circle is about — not theory, but actual practice. What to expect: 🗣️ A short opening round — a few words on how you’re arriving 🧭 A brief framing of the theme 🌀 Guided somatic practice — breath, presence, and gentle inquiry 💬 Space to reflect and share, if you want to It is a free event!

**SUSE X I-share:** **Sprekers:** * [Hugo de Vries](https://www.linkedin.com/in/hugo-de-vries/) (Solution Architect) * [Bert Boerland](https://www.linkedin.com/in/bertboerland/) (Account Executive) * [Keown de Koning](https://www.linkedin.com/in/keowndekoning/) (Head of Channel) **Beschrijving** ''Tijdens deze sessie nemen we je mee door het brede SUSE-portfolio. Van de betrouwbare basis van SUSE Linux Enterprise Server (SLES) tot multicluster Kubernetes-beheer met Rancher en zero-trust containerbeveiliging met SUSE Security: SUSE biedt een compleet, onafhankelijk open-source ecosysteem van besturingssysteem tot cloudtechnologieën. We starten met de basis van SUSE en kijken terug naar de ontwikkeling van een Duitse open-source pionier in 1992 tot een wereldwijde enterprise speler van vandaag. Daarbij prikken we door de marketingverhalen heen en delen we praktijkvoorbeelden van organisaties die het volledige SUSE-portfolio inzetten om complexe infrastructuuruitdagingen op te lossen. Ook laten we zien hoe klanten de overstap maken van een Amerikaans georiënteerde infrastructuur naar een Europees alternatief. Tot slot geven we een live Rancher-demo, waarin je ziet hoe alle componenten naadloos samenwerken om moderne IT-landschappen te beveiligen, beheren en schaalbaar te maken. Wat kun je verwachten: * **Het volledige SUSE-verhaal** Hoe een Europese open-source pionier een complete technologiestack heeft opgebouwd – van operating system tot Kubernetes. * **Meer dan alleen containers** Inzicht in het bredere portfolio (Linux & Cloud Native) en waarom dit aansluit bij de behoeften van moderne enterprises. Inclusief mogelijkheden om jezelf hierin te laten opleiden tot specialist. * **Praktijkvoorbeelden uit de markt** Hoe organisaties het volledige ecosysteem gebruiken voor stabiliteit, compliance en schaalbaarheid en waarom SUSE steeds vaker de nieuwe standaard wordt. * **Live demo** Zie het portfolio in actie en ontdek hoe SUSE de volledige keten verbindt: van infrastructuur tot en met de applicatielaag. Of je nu infrastructure architect, platform engineer of security specialist bent: sluit aan en ontdek waarom het SUSE-portfolio perfect aansluit op jouw moderne infrastructuurstack!'' *Het programma zal deze avond als volgt zijn:* * Vanaf 17.15 u: inloop * Rond 17.30/18.00 u: eten * 18.30 u: start sessie * 20.00 u: afsluiting We zien jullie graag dan!

**Welcome to our June UX Beers in Antwerp!** This time, we will host our event on Tuesday the 30th of June at Craftzing in Antwerp. [Ariad](https://www.ariadgroup.com/) and [Creative Skills](https://www.creativeskills.be/) sponsor our events. Follow the event online? We stream live via [Youtube](https://www.youtube.com/watch?v=EBqyTDAyQBw) \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\- \#\#\# UX TALKS **Talk 1:** **UX with AI: Did we all just get promoted?** By An-Sofie Rombouts, Product designer @ Gorilla Working in a startup often means designing without established UX processes. So with AI emerging, it can feel like a lifeline: faster prototyping, '*deeper*' research, and more concepts to explore. But somewhere between the third AI-generated prototype and losing the thread of your prompted designs, it can become painfully obvious what the impact is of designing with LLMs. We're not executing anymore, we're reviewing, approving, and critiquing, like a manager. This talk gets honest about what that actually means: the speed gains are real, but the cognitive debt is quietly compounding, and your future as a designer depends on understanding why. Explore how designers can protect their cognitive depth, enhance their review capacity, and stay in control when the machine can almost draw anything. **Talk 2:** **Growing UX in organisations that are not there yet.** By Koen Peters, Designer at Namahn More and more organisations are asking us to help build design expertise in-house, even putting together a design team for them. I have learnt that in such cases, you need to set aside your own biases and assumptions first: your neatly mapped-out methodology, your Figma dogmas and all the other things you as a design agency take for granted. The reality in these organisations is often very different: limited resources, no design culture and few or no trained designers on the team. Through a few client case studies, I will show how we have tackled such challenges. Organising a training in UX and design thinking is a good first step, offering a chance to get to know the team and identify which skills are already there and which are missing. I will also demonstrate tools and activities that we have used to help a team get started and become more aware of UX research and design. These include a script for choosing the right UX approach, skills assessment models to identify gaps and first steps towards creating a design playbook. \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\- \#\#\# SCHEDULE 18:00 - Doors open. Drinks & snacks 19.00 - 19.15 - Introduction to UX Belgium Meetup, announcements 19.15 - 19:45 - Talk #1 19:45 -20:15 - BREAK 20:15 - 20:45 - Talk #2 20:45 - 21:30 - Socialize \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\- \#\#\# SLACK CHANNEL We have our own UX Belgium slack channel. [Come join us and say hi!](https://join.slack.com/t/ux-belgium/shared_invite/zt-1bjpnuiog-T4Di4flXYPWgbT9KrZ53CA) \*\*\* \#\#\# YOUTUBE CHANNEL All our livestreams and talks are recorded and available on our [UX Belgium youtube channel](https://www.youtube.com/channel/UCno7V18T-EglYXprgrUZQ7A). \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\- \#\#\# ABOUT UX BELGIUM UX Belgium is a growing community of User Experience (UX) professionals in and around Belgium. Look for these types of events: UX Beers Periodically, we gather at a different agency or venue to drink beers, network and listen to speakers on various themes in the world of UX and digital design. UX Antwerp: Each last Tuesday of the month UX Brussels: Each second Tuesday of the month, 4x per year UX Workshops Now and then we organize events to dive deeper into specific skills and techniques in UX. These are smaller, hands-on workshops designed to boost your UX toolbox. \*\*\* The UX Belgium Meetup Team