Outdoor Tennis

Beste Java-ontwikkelaar, We nodigen je graag uit voor een fysieke Java Meetup bij de Belastingdienst over **DDD, Event Storming en Hexagonal Architecture** door Arjen Wassink & Cees van der Velde van Quintor. **Programma:** 17:45 Inloop 18:00 Indonesisch buffet (halal, koosjer & vegetarisch) 19:00 Presentatie **Domain Driven Design / Event Storming** 19:45 Pauze (koffie/thee) 20:15 Presentatie **Hexagonal Architecture** 21:00 Drankjes met hapjes 21:30 Afsluiting De presentaties worden in het Nederlands gegeven. **Betere systemen ontwikkelen met hulp van DDD, Event Storming en Hexagonal Architecture** Je hebt het vast wel eens meegemaakt dat je een software systeem onder handen krijgt die niet makkelijk te onderhouden, upgraden of uit te breiden is. Iedere aanpassing lijkt exponentieel veel tijd te vergen. Er kunnen verschillende oorzaken hiervoor zijn, maar vaak zie je dat er te veel afhankelijkheden in de sourcecode zijn, verantwoordelijkheden niet goed belegd zijn of het systeem niet goed aansluit op de werkelijkheid. In deze sessie gaan we in op hoe DDD, Event Storming en Hexagonal Architecture ons kan helpen deze punten te verbeteren aan de hand van een concrete casus, diagrammen en sourcecode. Zo gaan we in op: * hoe Event Storming kan helpen de brug te slaan tussen de ‘business’ en developers, zodat een systeem aansluit op de werkelijkheid * DDD artefacten input leveren voor het bepalen van een systeemarchitectuur met duidelijke verantwoordelijkheden en afhankelijkheden * Hexagonal Architecture handvatten biedt voor een software architectuur met minder functionele- en technisch afhankelijkheden Mis deze inspirerende kennissessie niet en ontdek hoe je jouw softwareprojecten toekomstbestendiger maakt! **Arjen Wassink** Arjen is een architect bij Quintor met 25 jaar ervaring in het bouwen, onderhouden en doorontwikkelen van verschillende soorten systemen met Java technologie. Met zijn brede techniek en vakmanschap interesse is hij instaat enterprise architecturen te vertalen naar systeem- en software architecturen, en werkwijzen die werken. Hiernaast verzorgt hij een minor cloud-native software development aan de Hogeschool Utrecht waarin hij nieuwe vakgenoten leert professioneel software te ontwikkelen voor de cloud. **Cees van der Velde** Cees is een ervaren business- en informatieanalist bij Quintor met een passie voor techniek. Zijn kracht ligt in het helder krijgen en begrijpen van vraagstukken en deze te vertalen naar een concrete oplossingen die aansluiten bij de behoeften van developers, zodat effectief het juiste systeem gebouwd wordt. **Deelname:** Deelname is gratis. **Locatie:** Belastingdienst Stationsplein 50 (naast het bus- en NS-station) 7311 NZ Apeldoorn **Opmerkingen:** * Vergeet uw paspoort of identiteitskaart niet mee te nemen. * Registreer met dezelfde achternaam als op uw paspoort of identiteitskaart. * Geef eventuele dieetwensen door, anders dan halal, koosjer en vegetarisch. * Wij raden u aan om met het openbaar vervoer of de fiets te komen. * Er zijn 30 parkeerplaatsen onder ons kantoor, navigatieadres Sophialaan 22 - 7311 PD Apeldoorn. * Overige parkeermogelijkheden: 1. Parkeergarage Haven-Centrum, navigatieadres: Korte Molenstraat 2 Apeldoorn, 2. P+R, Laan van de Mensenrechten Apeldoorn.

**3D Workshop** * **Ontwerpen met Fusion360** * **Scannen in 3D** * **Het gebruik van 3D printers** **Je bent nu welkom in de nieuwe locatie NewTechPark** Je kunt ook online aan deze fysieke bijeenkomst deelnemen. De bijeenkomst is dan op de locatie te volgen. Als je [hier](w.j.put@hccnet.nl) vooraf een mailtje stuurt kun je dinsdagavond tussen 19.00 en 20.00 uur inloggen met Jitsi voor vragen, of ter kennismaking met hcc!3D. Online neem je deel aan de bijeenkomst met [https://wij.hcc.nl/3D](https://wij.hcc.nl/3D) [(Alleen toegang als je zichtbaar bent met voor- en achternaam. )](https://wij.hcc.nl/3d)

We delen onze doelen en maken plannen voor de komende week. Iedereen is welkom. We kijken er naar uit om jouw verhaal te horen.

**Welcome to our February UX Beers in Antwerp!** This time, we will host our event on Tuesday the 24th of February with [Ariad](https://www.ariadgroup.com/en) at [Plein Magazijn](https://www.pleinmagazijn.be) 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: Align or Fail: When Brand Meets UX** [Mario Restrepo](https://www.linkedin.com/in/mario-restrepo/), Creative Director Every interaction shape perception and tells a brand story, whether intended or not. In this talk, we explore why UX is the space where brand promises are either proven or broken, and why, in the age of AI, alignment between brand and user experience has become a strategic imperative. Drawing on real-world examples, this talk reframes UX designers as brand storytellers, and UX deciders and stakeholders as guardians of trust. It also introduces an **AI-driven Brand Sentiment Analysis workflow**, showing how teams can translate user signals into actionable insights, and design experiences that don’t just function, but reinforce how a brand is felt, remembered, and believed. **Talk 2: The UX evolution: thriving in the age of intelligent systems** [David Grunewald](https://www.linkedin.com/in/davidgrunewald/), Founder of Pluginto.ai , AI-Strategist AI is fundamentally changing how UX professionals work, but it's amplifying our capabilities, not replacing them. This 45-minute session explores what's actually happening in 2026. You'll see real implementations from banking, healthcare, and other sectors: proactive systems that anticipate needs, conversational interfaces that adapt to individual patterns, and hyper-personalisation at scale. We'll examine **four trends reshaping UX practice and, more importantly, what they mean for your daily work**. What's being automated? What's gaining value? And what are the five essential skills that set you apart in an AI-augmented world? You'll leave with clarity on how to evolve your practice and confidence that your human expertise remains your competitive advantage. \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\- \#\#\# 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 Hasselt: 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

Join us for an evening of good vibes! Whether you’re a local or an expat, Mingle Mania is the perfect place to socialize and make friends or even to practice languages. ‍♂️‍♂️ Join [https://chat.whatsapp.com/GopSuzuFKRBKeYVKQrX4pE](https://chat.whatsapp.com/GopSuzuFKRBKeYVKQrX4pE) The group has many regular members, we intend to do various type of events, the goal is to build a strong community for all sorts of activities. If you have an event idea that you would like to see happen, let us know. We generally have about 20 participants, the age is between 20 and 60 averaging somewhere around 30, language exchange is not strictly enforced, culture exchange happens naturally. **mingle** (verb, intransitive): to move among people and talk to them, especially at a social event. **What We Are:** * A diverse group of locals and expats * ...going out at least every Tuesday **Event Details:** * It is free to join and operated on a voluntary basis! * Please honor the bar by ordering at least one drink.

Every Tuesday, the group 024 Waalrunners goes for a run at a distance of between 5km - 10km. Everyone is welcome to join, you just need to turn up at 20:00 on Tuesday in front of Cafe De Hemel. There are different routes every time, and the group welcomes all new people to join them. After the run we usually stay for a drink at De Hemel. https://waalrunners.activedates.nl https://chat.whatsapp.com/CRXG7x9HQUw4Q1qCrNzXn4?mode=ems_copy_t https://www.facebook.com/024waalrunners-710731759317504

** ABOUT OUR WATERCOLOR PAINTING PARTY / AMERSFOORT** Amersfoort - Utrecht Province / Center of the City / Easy access from train station. Create your very own **portrait, animals, landscape, or figurative** masterpiece in only **2.5 HOURS using watercolor and our secret mixed media techniques!.** This session is not about perfection; it is about capturing emotions and personal expression. **No experience required** **\- trust us\!** our professional artist will guide you step-by-step through this unique self-portrait journey. You can look forward to a fun and exciting evening with other participants, **so it doesn't matter if you want to come with friends or alone - you are very welcome!** This is the perfect after-work or weekend activity where you'll unleash your creativity while creating something deeply personal. You will create a portrait combining painting, drawing, and creative techniques to bring your unique vision to life. When finished, you'll take home your newly created self-portrait artwork to cherish or share with loved ones. Each participant will have pencils, colored pencils, watercolor, acrylic/gouache paints, and a surface. You'll work from an image we will bring. **️ READY TO HAVE FUN?** Get your Ticket and book your seat **✨[HERE](https://buymeacoffee.com/artloversclub/e/430555) ✨** **Questions?** Speak with a member of the team in **[WHATSAPP HERE](https://chat.whatsapp.com/J3Y5yeWUhvbJM98bqty2WP) ** .................................... ** WHAT'S INCLUDED?** All supplies included **2.5-HOUR [TICKET SESSION](https://buymeacoffee.com/artloversclub/e/430555)** ️ **EXTRA BONUS:** **FREE TICKET**️ to participate in our Drawing and Painting Cafes in Amersfoort or Our Online Still-Life sessions if you live far away. New friendships and Conversations Freedom to work at your own pace **English tutored activity** (And of course, you can speak in your local language with your friends!) ⭐ No experience needed **️ BOOK YOUR SEAT IN ADVANCE ✨[HERE](https://buymeacoffee.com/artloversclub/e/430555) ✨!** **Questions?** Speak with a member of the team in **[WHATSAPP](https://chat.whatsapp.com/J3Y5yeWUhvbJM98bqty2WP) ** ** 2026 CALENDAR OF UPCOMING EVENTS:** First Sunday or every month from 11.00 AM - 1:30 PM. .................................... **️ ART LOVERS CLUB / ABOUT US** **ART LOVERS CLUB** is a community where art enthusiasts come together to explore their creativity and connect with new buddies through various events and sessions ( In-Person and Online) . Whether you're a seasoned artist or just starting, we have something for everyone!⭐ To share with you more about what we do, you can see here the overall atmosphere of our events in Amersfoort and also follow us if you want⭐: **[https://www.instagram.com/art_lovers_social_club](https://www.instagram.com/art_lovers_social_club)** **Questions?** Speak with a member of the team in **[WHATSAPP](https://chat.whatsapp.com/J3Y5yeWUhvbJM98bqty2WP) ** ** 2025 CALENDAR OF UPCOMING EVENTS:** First Sunday or every month from 11.00 AM - 1:30 PM. **See you soon. We are looking forward to painting and having Fun Together! ‍‍‍‍**

This circular walk begins at Nijmegen Heyendaal train station and takes us through some forests to the south of Nijmegen. We’ll walk through Brakkenstein park, then a tranquil botanical garden (Stichting Hortus), then into the Dekkerswald woodland estate. Further south we will walk through the north part of the Groesbeekbos and stop for refreshments at the Boscafé de Zweef. Then we walk northward again through the pine forests of the Heumensoord and the leafy University grounds to get back to the station. The walk is mostly flat, but features mostly rough/uneven paths so it is recommended to wear sturdy walking shoes. As always, remember to bring water and maybe some snacks.

Hi✋ At[ Data Tribes ](https://www.datatribes.nl/)we organise Meetups because we truly care about sharing knowledge both inside and outside the organisation. We believe that it is beneficial to us and to the market as a whole to connect, create, learn and grow together! **The agenda** // Doors open 6.00pm // Drinks and Pizza’s 6.30pm // Start presentations 7.00pm **Henk van der Valk:** "Optimizing the Azure cloud?" ***Who really cares about Cost & Co2?*** // Start networking 9.00pm // End Meetup 9.30pm Greetings, Data Tribes Inc.

Donderdag **26 februari 2026** is het weer tijd voor onze **Techday**: hét vaste moment waarop we kennis delen, elkaar inspireren en nieuwe ideeën direct in de praktijk brengen. Deze editie komt een spreker van Onyx langs. Onyx is gespecialiseerd in cybersecurity. Tijdens deze techday worden theorie, praktijk en nabespreking gecombineerd met directe toepasbaarheid in jullie dagelijkse werkzaamheden. Tijdens de Techday duiken we hands-on in veelvoorkomende kwetsbaarheden en misconfiguraties binnen moderne softwareontwikkeling. Theorie, demo’s en realistische scenario’s wisselen elkaar af. Met de interactieve CTF‑opdrachten leer je niet alleen hoe deze problemen ontstaan en misbruikt worden, maar vooral hoe je ze direct kunt toepassen en voorkomen in je dagelijkse werk. **Wanneer:** Donderdag 26 februari 2026 **Wat:** Cybersecurity in de Praktijk: Hands-on met Onyx **Voor wie:** Iedereen die nieuwsgierig is en wil leren **Agenda** 14:45 - 15:00 - Inloop 15:00 - 18:00 - Opening en introductie Praktijkvoorbeelden: Wat zijn wij in het echt tegengekomen Security misconfiguration: Gezamelijke spot-de-fout met code-snippets CTF opdrachten 18:00 - 19:00 - Eten en napraten We zien je graag op de Techday!

**ArnhemJUG** We are excited to announce the second meetup of 2026. OpenValue Arnhem is once again hosting us for the February meetup! **Agenda** * 17:00 CET walk-in * 17:30 – 18:30 Food and drinks * 18:30 – 19:30 talk: **Catching the 137-Killer: A Java Memory Forensics Investigation** by **Martijn Dashorst** * 19:30 – 19:45 break * 19:45 – 20:45 talk: **Building AI Agent Platforms: Architecture, Communication, and Standards** by **Pascal Wilbrink** * 20:45 – 21:30 drinks **Catching the 137-Killer: A Java Memory Forensics Investigation** Your Java application is running smoothly, blissfully unaware of the danger lurking just around the corner. Then—without warning—it vanishes without a trace. Upon investigation, you discover the virtual remains of countless slain JVMs, each marked with the same cryptic number: 137. A serial killer is on the loose in your cluster. This true crime investigation will walk you through the differences between JVM memory areas, the mechanics of container OOMKills, analysing Grafana dashboards for memory and thread anomalies, interpreting heap dumps, and utilising JVM Native Memory Tracking (NMT) to uncover hidden native memory consumption. You’ll master practical forensic techniques and proven prevention strategies—from memory tuning tactics and balancing heap vs. non-heap allocations to leveraging large language models (LLMs) for advanced forensic analysis. These skills will help ensure your applications stay alive—even when something’s out to get them. Just like in a real murder mystery, we may not know whodunnit... but with Martijn Dashorst leading the investigation, you're sure to get closer to the truth. **About Martijn Dashorst** My Java experience is finally old enough to drive, vote and drink a beer (not all at once). One of the remaining Eclipse users, loves Java, relationship with Maven is complicated. Martijn Dashorst has worked since 2004 at Topicus and has used Java since 2002. Loves server-side Java. You might know him from Apache Wicket—he's dabbled somewhat in that framework. Loves his family and cats, finds Douglas Adams' description of the Sirius Cybernetics Corporation's technology very apt to the current technology landscape. **Building AI Agent Platforms: Architecture, Communication, and Standards** AI systems evolve from standalone models into connected, agent-based ecosystems, new architectural patterns, protocols, and standards are emerging. Concepts such as AGUI, A2A, A2UI, and MCP-based applications are changing how intelligent systems are designed and integrated. This presentation explains how these approaches affect system structure, responsibilities, and interoperability. Using architectural diagrams, it shows how AI agent applications communicate and collaborate through standardized interfaces, and provides guidance on building scalable and maintainable AI platforms. **About Pascal Wilbrink** Pascal is a senior software engineer at OpenValue with over a decade of experience and a strong interest in applied AI and intelligent automation. He enjoys exploring how technology can make developers’ lives easier and software more resilient. When he’s not experimenting with new ideas or building open-source tools, Pascal likes to learn by doing and turning complex problems into practical solutions.

**How does a TennisColumbus Season / League run?** The league advertises the season dates and builds a queue of committed players for the season. **Kickoff Day - March 26th** The start day of the season, players are sent a kickoff email that contains important information about the league, the link where your league standings and players contact information. We guarantee 6 playing partners at your playing level, but have been averaging closer to 15+ partners in most cities. The number of different levels we run is solely based upon the number of players enrolled for the league kickoff. Typically we are running a Skilled-3.0, Competitive-3.5 and Advanced-4.0 in most cities. **Your Task - "Flexible Scheduling"** After this kickoff email is sent, it is the **player's task to communicate with other players**. Players should work with their partners to find an agreeable time and location to play the match. While TennisColumbus doesn't mandate your playing schedule, it is recommended that players schedule at least one match per week. By request of the players, we started to allow players to play 1 rematch per season. The regular season is all about playing as much as you can. As of Feb. 10, 2026 we've had an amazing 2,017 players play more than [20 matches in a season](https://www.tenniscolumbus.com/info/MatchesInSeason). **Where to Play?** Play at your local free tennis courts, tennis parks, condo courts or tennis clubs. The league strongly suggests that players jointly try to pick a tennis court location convenient to both. We provide an extensive list of [tennis courts](https://www.tenniscolumbus.com/TennisCourts), including # of courts, lighting, hitting walls, etc. We strive to keep this list up-to-date. TennisColumbus sets up a must play dates to push players out on the courts. The final deadline is the date marking the end of the season, at which point players with 3-5 wins (Actually total is specified on the division page) will qualify for a post-season playoff to determine the league champion. **How to Play?** Players can use three mostly standard playing formats: 2 out of 3 sets, 2 sets with 10 point super tie-breaker or the 10-game pro set (First to 10, used when court time is limited). On Feb. 2018, we added Fast Tennis 4 game pro set format as a valid format. **Playoffs** Each season concludes with a playoffs where players with anywhere from 3 to 5 season wins qualifies for a single elimination tourney. The champion is awarded based upon the league [Prize Pool](https://www.tenniscolumbus.com/info/prize_pool3). Each singles league champion also receives a playing entry into one of two national championships we run. **[JOIN TODAY](https://www.tenniscolumbus.com/join)** Full price is $39.95 to play in a season. The earlier you sign up we typically offer discounts during these tough economic times. Just go to the [Join Page](https://www.tenniscolumbus.com/join) and complete the short form. We'd be happy to find you dedicated tennis playing partners.

The Fitness Experience This is not just a workout—it’s a vibe. The Fitness Experience is a high-energy, feel-good outdoor fitness meetup designed for every body and every level. Whether you’re just getting started, getting back into it, or already living an active lifestyle, this experience meets you where you are and pushes you just enough to level up. Expect movement, fresh air, challenges, laughter, and real community. We sweat together, encourage each other, and stay accountable—because consistency is easier with friends! Motivation with meaning: ✨ Show up for yourself ✨ Progress over perfection ✨ Consistency creates confidence Each month, we pop up at a new scenic outdoor location—parks, waterfronts, city greenspaces, and hidden urban gems—bringing fitness to life in the most inspiring settings possible. Come solo. Bring a friend. Leave energized.

We’re still working to get more people into these Meetups, but our goal is to give PlayYourCourt members a few social tennis outings each week in addition to your practice sessions and Challenge League matches. These Meetups are co-ed, super laid back, and all skill levels are welcome. Post your skill level and a suggested court in the comments section so we can round up as many players as we can for some tennis fun! Also, if you’re looking to meet new practice partners or play some matches and you aren’t already in the PlayYourCourt Community, you can go here to see what we’re all about and sign up: https://www.playyourcourt.com/tennis-community/columbus-oh/meetup/ If you love tennis, we’d love to have you! Be sure and watch the quick video that explains how everything works. Happy hitting! - Scott

We’re still working to get more people into these Meetups, but our goal is to give PlayYourCourt members a few social tennis outings each week in addition to your practice sessions and Challenge League matches. These Meetups are co-ed, super laid back, and all skill levels are welcome. Post your skill level and a suggested court in the comments section so we can round up as many players as we can for some tennis fun! Also, if you’re looking to meet new practice partners or play some matches and you aren’t already in the PlayYourCourt Community, you can go here to see what we’re all about and sign up: https://www.playyourcourt.com/tennis-community/columbus-oh/meetup/ If you love tennis, we’d love to have you! Be sure and watch the quick video that explains how everything works. Happy hitting! - Scott