Test Driven Development

**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.

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!

Andrew Fray is back to present his talk on "Productive and Pragmatic Prototype Programming". The Game Dev Group is a chilled, friendly place for anyone interested in game development to meet, learn and collaborate together. **The Speaker for this event is Andrew Fray.** Andrew is an automated testing consultant, speaker and developer with a background in programming for studios like SEGA, Codemasters, SpryFox and Roll7. He will be sharing high-level insights into programming with prototyping in mind and how it differs from programming for production. Structure: 6:30PM - Doors Open - Bar Snacks, Drinks, Networking/ Chatting 7:00PM - Introduction and Talk Begins 8:30PM - Talk Finishes, More Chatting, More Snacks, More Drinks 9:30PM - Last Orders Please let your game dev friends and colleagues know about this group too. We hope to build it into a great resource for the community over the coming months and years. 1 Mill Street is the incredible home of TheGDG, a place designed to blur the lines between work and play. For more information about the co-working facilities, podcast studio or event space, check out their website. Maverick Games is a UK-based independent video game studio, focused on creating premium open-world AAA titles for consoles and PC. The studio champions a developer-first culture that encourages creativity, bold ideas, and risk-taking to craft innovative gaming experiences. Playground Games are an award-winning studio based in the heart of Leamington Spa. They have built one of the biggest franchises on Xbox with Forza Horizon, and are currently building one of the most highly anticipated games of the decade: Fable. They are recruiting across both teams, so check their website to see if there is a role for you! Code Wizards Group – Code Wizards and Multiplayer Wizards – help studios build and run games that players love. Their company specialises in video game consulting services for backend elements, powering up gaming projects with expert gametech, esports-tech, and LiveOps services for game dev professionals and studios. Rebellion is an independent video games studio that also produces books, comics, TV, Film, board games, etc. They make great games such as the genre-defining Sniper Elite series and Zombie Army, and before 2010 have worked on multiple amazing external projects including the likes of Aliens vs Predator and Star Wars Battlefront. Creare Capital is a financial platform dedicated to empowering small and medium-sized enterprises (SMEs) and freelancers in the creative industries by connecting them with tailored grants, loans, and investment opportunities. Their mission is to bridge the gap between finance and creativity, offering inclusive, flexible funding solutions that help creative businesses grow and thrive. Sorcery.gg is a jobs platform built by game devs, for game devs. The platform is one of the biggest in the industry, with over 15,000 roles listed. Sign up for an account and start your hunt. Black Cat Entertainment is an indie studio focused on supporting junior game devs get their chance in the industry. In order to show appropriate respect to the organisers, speakers, and your fellow community members, please ensure you attend if you RSVP! See you there! A disclaimer: This event is intended for an audience of people aged 18+ and alcohol will be present. Anyone under the age of 18 must be accompanied by a responsible adult.

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.

Een avond in een ontspannen sfeer voor alle leeftijden. Geniet van een drankje van ons en ontmoet nieuwe mensen. Je kunt alleen komen of samen met een vriend(in). Tijdens de avond maak je makkelijk contact met anderen die ook op zoek zijn naar betekenis. Meld je aan en kom bloeien! Tijdens deze bloeiklas maken we tijd vrij voor een gezonde dosis zelfreflectie. Er is zoveel mogelijk! Fijn natuurlijk, maar soms ook best ingewikkeld. Want hoe maak je dan goede keuzes? En hoe ga je om met alle verwachtingen van de maatschappij, je omgeving en natuurlijk van jezelf? Belangrijke vragen in een tijd van burn-outs, keuzestress en prestatiedruk. Met meditatie, visualisatie en creatieve werkvormen gaan we dieper in op onze verlangens, drijfveren en (on)bewuste overtuigingen. Tegelijkertijd halen we de druk van de ketel, want willen we niet te veel? We zijn constant in ontwikkeling, verkennen vele opties en proberen de beste keuzes te maken. Wat heb jij nodig om te bloeien? Met de inzichten van de Duitse filosoof Byung-Chul Han gaan we op zoek naar de vrijheid in onze prestatiesamenleving en met David Brooks’ bestseller ‘De Tweede Berg’ duiken we in de vraag aan welke roep je gehoor moet geven, als er van alles om ons heen roept. Meer weten of hiervoor aanmelden? Bezoek de onderstaande link: https://www.dekwekerij.org/bloeiklas/utrecht-ontdekken/

¡Compartamos juntos con el grupo de personas más divertido de la ciudad!... ¡en español! No necesitas ser un hablante fluido o nativo.... ¡Solo atrévete a compartir! Te esperamos a las 20hrs.... ¡Entrada gratuita! ¡Nos vemos! ¡Hasta entonces! 😃 Let's share together with the funniest group of people in town!... in Spanish! You don't need to be a fluent or native speaker.... Just dare to share! We wait for you at 20hrs ....Free entry! Nos vemos! Tot dan! 😃 Facebook Group: https://www.facebook.com/groups/habladores/ Meetup Link: https://www.meetup.com/nl-NL/los-habladores/ Instagram page: https://www.instagram.com/los_habladores_utrecht/ Los Habladores!

Wil je op een laagdrempelige manier van gedachten wisselen over hoe we de toekomst van Flevoland en Europa kunnen vormgeven? Of wil je in gesprek over nieuwe, progressieve ideeën? Kom dan naar ons maandelijkse Politiek Café LIVE en praat mee over de toekomst! #### **Wat is Politiek Café Live?** Politiek Café Live is een open en informele ontmoetingsplek voor iedereen die geïnteresseerd is in de politiek van Volt. Of je nu lid bent of gewoon nieuwsgierig, je bent van harte welkom. Elke maand gaan we in een ontspannen sfeer met elkaar in gesprek over actuele thema's die spelen in onze provincie en daarbuiten. #### **Wanneer?** Politiek Café Live vindt elke maand plaats. Zie voor overige data en events: https://voltnederland.org/flevoland/agenda #### **Voor wie?** Voor iedereen! We zijn een open beweging en geloven dat de beste ideeën ontstaan als we samenwerken en verschillende perspectieven overwegen. Neem gerust een vriend, buurvrouw of familielid mee.

**(Tickets + event access exclusively available through EventBrite.)** Full event link here [From Fixed to Flow - EventBrite](https://www.eventbrite.nl/e/from-fixed-to-flow-an-online-workshop-of-creativity-and-release-tickets-1981557382473?aff=oddtdtcreator) Loosen the mental knots you didn’t know you were tightening. Use creativity to move from fixed patterns into more open habits. Refresh yourself before a new week with an easy, online workshop to open your mental well-being through creative mindset from a stuck sense of routine to more flexible state. \*\* What You'll Experience:\*\* * **Structured, guided conversations** where thinking out loud is part of the method. It's not a lecture, and it is a blend of psychology, art, and practical ritual. * A **live, interactive exercise** to break rigid thinking and experience "flow." * A **supportive space to connect** with others feeling the same desire for more lightness and less rigidity. **️ What You'll Take Away:** * **The "Separation of Tasks" Tool:** A philosopher's secret to deflating anxiety about others' opinions. * **The Conduit Mindset:** How to replace "Is this good?" with the liberating question, **"What happens if you stop deciding in advance what ‘good’ looks like?"** * **Your First Micro-Ritual:** A simple, 5-minute daily practice to make creativity an inevitable source of calm. * **Clarity & Permission:** A clear map to identify your "Fixed Self" and the courage to gently unfurl from it. **✨ This is for You if:** * You feel mentally "stuck" or confined by your routines. * You've ever said, "I'm not a creative person." * You long for more playfulness, less pressure in your daily life. * You desire to use creativity as a tool for well-being, not just output. * You are 18+ years of age. \*\* Workshop Details:\*\* * **Duration:** 90 minutes * **Format:** Live, interactive virtual session (Link provided upon registration) * **Investment:** €7 less 15% off through 1 March * **What You Need:** A quiet/comfortable space, a willingness to be gently curious, and one ordinary object within arm's reach (a pen, a cup, a book). **(Tickets + event access exclusively available through EventBrite.)** Full event link here [From Fixed to Flow - EventBrite](https://www.eventbrite.nl/e/from-fixed-to-flow-an-online-workshop-of-creativity-and-release-tickets-1981557382473?aff=oddtdtcreator)

Join us for a night of fun and games at our local community center! What to Expect: * Free entrance for everyone! * Bring your favorite games * Meet new friends and gaming enthusiasts * A night of exciting challenges and friendly competition * Bring your own snacks and refreshments Whether you're a board game aficionado or a video game guru, this event is for you. Don't miss the chance to connect with fellow gamers in our community! This event is part of an ongoing series organized through our Discord server [[discord.gg/utrecht](http://discord.gg/utrecht)], where we've had the pleasure of hosting quite a couple of gatherings in the past. Whether you're a seasoned regular at our events or someone new to the scene, we're excited to welcome you.

**🟢🟢 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! 🎨👩🏼‍🎨👨🏼‍🎨👩🏼‍🎨🧑🏼‍🎨🎈**

JULIANALAAN 100 park Angerenstein ( Entrance )

Join Creative Table for an interactive and fun Create & Connect session in Apeldoorn aimed at fostering community building. Unleash your creativity in a supportive and inclusive environment, where members can connect, share ideas, and collaborate on various art projects. Whether you are a seasoned artist or just looking to dabble in something new, this event welcomes all skill levels. Come prepared to mingle, create, and be inspired by the diverse talents within our community. Let's paint, draw, and sculpt our way to stronger connections and lasting friendships.

Give your still good laptop a second life instead of ditching it because Windows 11 says it is no good... Or you heard Linux is cool. If you have a backup of your data, that is great, else indicate that you do not, so we can help you. Do so in an extra message, else I don't receive your information. Geef je laptop die het nog prima doet een tweede kans in plaats van hem af te schrijven omdat Window 11 dat zegt... Of omdat je hoorde dat Linux gaaf is. Als je al een backup van je data hebt gemaakt is dat perfect. Of verwacht je dat wij dat doen? In dat geval graag aangeven hoe vol je harde schijf nu is... Doe dat in een extra bericht, want de info komt anders niet door.

## Overview Networking event for aspiring school leaders interested in building their own high-quality K-12 public school in their community. **About the Event:** Aspiring school founders in the Columbus, OH, area are invited to join us for this special in-person networking event where you will be able to ask questions, learn more about the BES Fellowship and make sure you are prepared for the application process and beyond. In addition to meeting like-minded leaders who are also committed to transforming education and bringing a high-quality K-12 option to their community, you’ll have the opportunity to meet our team and gain special insights from Dr. Chaundria Smith, BES Senior Director of Fellowship Coaching, who works closely to support BES Fellows. During this event, you can also learn more about the various regions across Ohio we are prioritizing for the BES Fellowship to ensure that new schools will respond to the needs of their community. **About the BES Fellowship:** Leaders in the BES Fellowship embark on a multi-year process to design, found, and lead an excellent K-12 public school that reflects and responds to community needs. We are currently accepting applications to the 2026 BES Fellowship. The extended deadline is March 30, and the 2026 Cohort will begin August 2026. Applications will be reviewed on a rolling basis until all spots are filled. Learn more at [bes.org/fellowship](http://bes.org/fellowship "http://bes.org/fellowship").

**Important time note:** Please plan on arriving between 5:30 and 6:00 as the elevators lock after 6 and you'll need to message us and we'll need to come get you. The building address is 4450 Bridge Park The entrance is 6620 Mooney St, Suite 400 You will need to scan your ID at the door to get a visitor badge. **Abstract** *Spec-Driven Development with GitHub Spec-Kit: From Intent to Implementation* Spec-driven development flips the traditional workflow on its head: instead of code being the source of truth, the specification becomes the backbone of design, collaboration, and delivery. In this session, we’ll explore how GitHub Spec-Kit enables teams to treat specifications as first-class artifacts—living documents that drive architecture, implementation, and verification. You’ll learn how Spec-Kit helps teams clearly express intent using structured, version-controlled specs that live alongside code. We’ll walk through a practical workflow that starts with defining system behavior and constraints, then progressively refines those specs into testable, automatable outcomes. Along the way, we’ll show how specs can reduce ambiguity, improve cross-functional collaboration, and make design decisions explicit before a single line of production code is written. This talk will cover: --What spec-driven development is (and what it isn’t) --How GitHub Spec-Kit fits into modern developer workflows --Using specs to align product, engineering, and AI-assisted development --Real-world examples of turning specs into implementations with confidence Whether you’re building greenfield systems, integrating AI into your stack, or trying to reduce costly rework, spec-driven development offers a scalable way to move faster without sacrificing clarity. Attendees will leave with concrete patterns and a clear mental model for adopting GitHub Spec-Kit in their own projects. **YouTube Link** TBA

Meeting @ Improving's office in Downtown Columbus, near Cosi. Parking is paid, food & drink are free! This time we're hanging out after the long winter break. We are going to look at a group-member's project used to help learn the fundamentals of Go, and if time allows, we can take a look at how we like to build Go projects using AI.

**PLEASE READ THE FOLLOWING IMPORTANT NOTES:** 1. The dates for this series are simply placeholders at the moment. We are working on our 2026 schedule, and adjustments are forthcoming. 2. Each class in this series has an attendance fee. 3. Each class from BOTH a sign-up and fee perspective is a separate entity. **Introduction:** Our Page Building with Bricks web development class provides detailed instruction for using Bricks Builder, a visual site builder for WordPress, to create and manage websites. Widely considered by many of the world's leading web developers to be the most complete page builder on the market today, Bricks Builder offers a wide range of features and comprehensive tools. Our Bricks Builder web development class provides detailed instructions on utilizing the toolset. The series of courses covers the core features of Bricks Builder, enabling users to design and develop responsive, visually appealing websites. Moreover, the courses are oriented to reinforce a focus on professional, scalable web development. Throughout the series, we focus our page-building instruction on the semantic and structural integrity of the pages in a responsive world. By the end of the 10-class series, participants will have a fundamental understanding of proper web page and website development. **The breakdown of the 10-class series is as follows:** * Class 01 - Survey of Page Builders / What Bricksbuilder Does For You * Class 02 - Boxes, Boxes, Boxes / Sections / Containers * Class 03 - Static Units / Relative Units / Responsive Development And Math Functions * Class 04 - CSS Variables And DRY Development / Classes And Global Styling * Class 05 - CSS Grid And CSS Flexbox * Class 06 - Responsive Development / Breakpoints And Media Queries * Class 07 - Effective Use Of Color / Effective Use Of Images * Class 08 - Beginning To Think Dynamically / Using Templates And Components * Class 09 - Dynamic Styling / Data Attributes And Attribute Selectors * Class 10 - Pseudo Elements / Programmatically Styling With Pseudo Classes Throughout the class sessions listed above, we cover the following key areas of web development with Bricks Builder: * **Introduction to Bricks Builder Interface:** * Familiarization with the builder's layout, including the toolbar, panel, and canvas, and understanding how to navigate and interact with its various components. * **Visual Site Building:** * Techniques for creating layouts using Bricks' drag-and-drop interface, incorporating sections, rows, columns, and elements to build page structures. * **Styling and Design:** * Utilizing Bricks' styling options to customize elements, apply global CSS classes for consistent design, and leverage features like Flexbox and CSS Grid for responsive layouts. * **Dynamic Content and Custom Fields:** * Integrating dynamic content from custom post types and custom field plugins (like ACF, Meta Box) to build data-driven websites. * **Template Building:** * Creating and managing reusable templates for headers, footers, post type layouts, and other site-wide elements. * **Performance Optimization:** * Understanding how Bricks Builder contributes to fast-loading websites and implementing performance best practices. * **Advanced Features:** * Depending on the class level, it might delve into advanced topics such as conditional logic, interactions, and custom code integration to enable more complex functionality. The series aims to equip participants with the skills to efficiently build, customize, and maintain WordPress websites using Bricks Builder, catering to both beginners and experienced web developers.

Join other experienced and aspiring agile coaches and professionals to: * develop and practice your coaching skills in a peer-to-peer environment * share current successes and challenges in your work environment and get support from each other * learn from each other, build better relationships and experiment with new ideas

Christians in Tech is a community at the intersection of faith and technology. Our meetups are designed to spark meaningful conversations, promote knowledge sharing, and encourage growth—both in your career and your spiritual walk with God. Whether you're an experienced professional or just starting your tech journey, CIT welcomes you. Our Website [https://linktr.ee/citcbus](https://linktr.ee/citcbus) Sponsors and Partners * Improving (Venue Sponsor) * Bethel World Prayer Center (Fiscal Sponsor) * Fruits & Roots (Coffee Partner)