Software Engineering

**📣** Welcome to **our second meetup in 2026!** Missed last meetup? Then its important you know that the Green Software Foundation and Sustainable IT Netherlands meetups, merged into one: **Sustainable IT Action NL!** Our mission is still to build connections around sustainable IT, exchanging ideas in a space for learning - and from there inspiring our members to take action. **🌿** We’re excited to gather peers who care about green, efficient, and responsible cloud practices on **April 23rd**, kindly hosted by **GreenPT** in Utrecht. **⏳ Time schedule** 17:30 – 18:00 Welcome 18:00 – 18:30 Vegetarian bites & networking 18:30 – 18:45 Kick-off & community introductions 18:45 – 19:15 Measuring the environmental impact of Google's AI - interactive explainer – Ozan Ogreden 19:15 – 19:45 Maryse Meinen– Holistic Digital Sustainability 19:45 – 20:00 Pitches 20:00 – 20:45 Drinks & networking **📍** 📍 **Location:** Plompetorengracht 4, Utrecht. GreenPT **❗ Capacity is limited to 50 participants, so please register early.** **✏️ Title: Measuring the environmental impact of Google's AI - interactive explainer** **💡 Speaker: Ozan Ogreden** **🍃 Abstract:** I built an "interactive explainer" that reproduces Google's methodology from Elsworth et al. (Measuring the environmental impact of delivering AI at Google Scale, Aug 2025, https://arxiv.org/abs/2508.15734). I'd like to share the explainer and my observations with the community. What stands out to me is a striking analytical (or rhetorical?) choice by Google team, which seems to be leading to a downward bias in headline-reported figures of their work. With the community, I'd like to attempt at two goals. One of them is a "narrow-minded goal", trying to find a charitable interpretation of what may have motivated Google's choices (specifically in the discussion related to measuring environmental impact of LLMs). The second is a goal with a more important perspective: Given our discussion, what's the best use of our time to move the needle in sustainable IT? *Ozan works at GreenPT:* GreenPT is a GPT-powered chat platform, and robust API, trusted by governments, businesses, privacy-focused organizations, and developers. Running on renewable energy and hosted in Europe for strict data protection, GreenPT gives you and your team the answers you need with a clear conscience and total transparency. [https://greenpt.com/](https://greenpt.com/) **✏️ Title:** Holistic Digital Sustainability **💡 Speaker:** Maryse Meinen **🍃 Abstract:** Less is More! This interactive session brings you inspiration and practical tips for embedding more sustainability all throughout your digital Product Development Cycle! Of interest for any role in the whole cycle of our process, from Product Owner to Agile coach and from business analist to tester! **📖 About the speaker:** Maryse works at the Rabobank improving our way of working and inspiring people to embed more sustainability in how we do Product Development. She is also a Stoic Practitioner. **🎤 Pitches** Our goal is connect people around Sustainable IT. In order to build more connections, we would like to offer the stage to everyone who wants to share something. We will timebox each pitch on 2 minutes exactly! Please note that this session is intended as a community gathering, so commercial pitches are to be avoided :) **🔎 Looking forward to seeing you there!** **👥 Organizing team** Tim van Bergenhenegouwen, Nick Batenburg (GreenPT, host) Wilco Burggraaf, Chris Stapper, Corina Milosoiu, Sabrina Hsieh (Sustainable IT Action NL)

Your monthly international comedy event in Nijmegen! Top European & UK headliners doing 1 night only in Nijmegen! Fancy some Thursday night laughs? Then come on over to Tierney’s Irish Bar & Restaurant for some top headline acts from the UK and European comedy circuits! The show sells out and space is limited - so please get your ticket soon if you are planning on attending. A table will be reserved for Meetups so you can enjoy the show together. Tix available via Eventbrite/ Tix4All and link below: https://fienta.com/nl/international-stand-up-comedy-attierneys-nijmegen Our headliner is Keith Fox, from Ireland. Regarded as “one of Ireland’s comedy gems” (Comedy Crunch), Keith has been a mainstay on the Irish comedy circuit for the past 10 years, headlining shows the length and breadth of the country. A charming and energetic performer, Keith’s stand-up blends clever observations with mischievous storytelling. He has performed to audiences across Europe, and at major festivals including the **Kilkenny Cat Laughs, Vodafone Comedy Festival, All Together Now, the Edinburgh Festival Fringe** and many more — an act not to be missed. As featured on Virgin Media TV, and FM104, and opening act for some for the finest acts in Ireland (Fred Cooke, Sinead Culbert, Ger Staunton and Martin Angolo). 'He is a class act!' - Fred Cooke 'Always knocks it out of the park' - Craic Den Comedy Club 'His anger is appealing' – Chortle An hilarious monthly show featuring some top names, a great night out with friends, a date, you work crew or just come alone and meet other comedy fans.

**Bitcoin Meetup met Crazy Pool!** Deze maand organiseren we iets leuks: voorafgaand aan de meetup (voor wie dat wil) spelen we Crazy Pool bij Timestamp op de Korenmarkt. Crazy Pool lijkt op minigolf, maar je speelt het met een keu en een bal die je door verschillende obstakels moet stoten. De speeltijd is ongeveer 45 minuten. Aansluitend eten we bij Flor Fina. Je kunt ook na het diner aansluiten als je alleen voor een drankje wilt komen. De Bitcoin Meetup is geschikt voor zowel beginners als ervaren bitcoiners. Stel je vragen en praat mee over de nieuwste ontwikkelingen in de wereld van bitcoin. Wil je meedoen met Crazy Pool of mee-eten? Laat het ons even weten, dan houden we daar rekening mee bij de reservering. * 16:30 — Crazy Pool @ Timestamp (Korenmarkt) * 17:30 — Diner @ Flor Fina (Korenmarkt) * 19:30 — Drinks @ Flor Fina (Korenmarkt) ## English Bitcoin Meetup with Crazy Pool! This month we’re doing something fun: before the meetup (for those who want to join) we’ll play Crazy Pool at Timestamp on Korenmarkt. Crazy Pool is similar to mini golf, but you use a cue to strike a ball through various obstacles. Playtime is about 45 minutes. Afterwards we’ll have dinner at Flor Fina. You can also join later if you only want to come for drinks. The Bitcoin Meetup is suitable for both beginners and experienced bitcoiners. Ask your questions and join the conversation about the latest developments in the world of bitcoin. Would you like to play Crazy Pool or join us for dinner? Please let us know so we can account for it when making the reservation. 16:30 — Crazy Pool @ Timestamp (Korenmarkt) 17:30 — Dinner @ Flor Fina (Korenmarkt) 19:30 — Drinks @ Flor Fina (Korenmarkt) ## Deutsch Bitcoin Meetup mit Crazy Pool! Diesen Monat organisieren wir etwas Schönes: vor dem Meetup (für alle, die möchten) spielen wir Crazy Pool bei Timestamp auf dem Korenmarkt. Crazy Pool ähnelt Minigolf, aber man spielt mit einem Queue und stößt eine Kugel durch verschiedene Hindernisse. Die Spielzeit beträgt etwa 45 Minuten. Anschließend essen wir im Flor Fina. Du kannst auch später dazukommen, wenn du nur auf einen Drink vorbeikommen möchtest. Das Bitcoin Meetup ist sowohl für Einsteiger als auch für erfahrene Bitcoiner geeignet. Stelle deine Fragen und diskutiere über die neuesten Entwicklungen in der Welt von Bitcoin. Möchtest du bei Crazy Pool mitspielen oder zum Abendessen kommen? Bitte sag kurz Bescheid, damit wir es bei der Reservierung berücksichtigen können. 16:30 — Crazy Pool @ Timestamp (Korenmarkt) 17:30 — Abendessen @ Flor Fina (Korenmarkt) 19:30 — Drinks @ Flor Fina (Korenmarkt)

Expand your visibility. Join a casual online hour to share you, your brand and business, and learn more about other business owners, locally and globally. Every session will close with gratitude and a mini creative activity, so have a pen and paper, tablet, or something available with which to write/create/draw. This usually occurs twice monthly. **RSVP here via EventBrite [here](https://www.eventbrite.nl/e/you-and-your-brand-a-casual-networking-hour-tickets-1984283125243).** *-* *\*\*\*The only requirements are a minimum age of 18 years old,* *and **at least three attendees** to make it a worthwhile hour for everyone.\*\*\**

**No skills. No plan. Just colour and flow.** **This is not a painting class.** This is a gentle space to relax, play, and express through color. *Come alone or with your friends.* **No painting or drawing experience required.** We start with *playful warm-up exercises* to get you out of your head and into the moment. Then, you’ll experiment with a *creative technique* we introduce, allowing you to explore freely on smaller sheets. In the second half, you’ll shift between: * a *slower, mindful creation round* * a *faster, intuitive expression round* **No rules. No perfection. Just flow.** ✨ Note: This is a pay what you feel event ***

Hi all, We’re back at Mick O’Connells and ready for another strong evening! We’ve got our own space again. Walk in, turn right at the bar, head past the dart boards, and you’ll find us in the side room. We've introduced a simple rotating format that gives you the chance to actually speak with everyone in the room. Short, focused conversations, good energy, and a lot more fun than it sounds. We’ll throw in a few conversation topics to get things going, but how you use the evening is entirely up to you. Come with intention, or don’t. Talk business, find clients, meet future partners, make friends, or just unwind with people who get it. We’re all building something, and we all have to roll with the punches. Only rule: you’re an entrepreneur, freelancer, or about to become one within the next 3 months. If not… the clock starts now ;) Try to arrive on time so we can kick things off properly. Can't find us? Look for the grey Gnome. He’ll guide you better than any sign ever could. See you there.

**Location:** 📍 Kingston University Penrhyn Road Library: Town House, Second Floor, Room: PRTH2028 **Date:** 📅 April 23\, 2026 \| 🕙 10:00 AM – 11:30 AM Join us for the official launch event of the **AWS Cloud Club @ Kingston University**! 🚀 We are a student-led community designed specifically for students to bridge the gap between your degree and the global tech industry. **What’s in it for you?** ☁️ * **The Essentials** 💡: We’re stripping away the jargon to explain what Cloud Computing actually is, why it's one of the most essential skillsets for graduates and how you can make the best use of AWS services for your career. * **The Big Four Services** 🛠️: Get a grip on the core services. Compute, Storage, Database and Networking that are used by millions of businesses worldwide. * **Gamified Learning** 🎮: See a live trailer for **AWS Cloud Quest**, the 3D RPG where you earn digital badges by solving real-world city problems. * **Exclusive Perks** 🎁: Learn what you can do in the AWS Free Tier and how to access **AWS Credits**, **Amazon Q** AI assistants and professional **Certification vouchers**. * **Leadership Roles** 👑: We are also recruiting our **Core Team**! If you want to help lead this community and build your personal brand, we want to meet you. **Note:** 📝 To help us grow, all attendees will be asked to provide brief feedback via a QR code at the end of the session. #AWSCloudClubs #KingstonTechSociety #CloudClubCaptains #StudentsBuildAWS

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 or to m10@m10tech.nl, 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 of aan m10@m10tech.nl, want de info komt anders niet door.

This session focuses on **Sparse and Ranking in Modern Retrieval**, featuring two speakers: **Simon Lupart** from University of Amsterdam and **Chuan Meng** from University of Edinburgh. **Location:** Science Park 904, Room C3.161 **Date**: Friday, April 24 **Time**: 16:00-17:00 **Zoom** **link**: [https://uva-live.zoom.us/j/65011610507](https://uva-live.zoom.us/j/65011610507) Details below: **Speaker #1**: **Simon Lupart** from University of Amsterdam **Title:** On the Challenges and Opportunities of Learned Sparse Retrieval for Code **Abstract:** Retrieval over large codebases is a key component of modern LLM-based software engineering systems. Existing approaches predominantly rely on dense embedding models, while learned sparse retrieval (LSR) remains largely unexplored for code. However, applying sparse retrieval to code is challenging due to subword fragmentation, semantic gaps between natural-language queries and code, diversity of programming languages and sub-tasks, and the length of code documents, which can harm sparsity and latency. We introduce SPLADE-Code, the first large-scale family of learned sparse retrieval models specialized for code retrieval (600M-8B parameters). Despite a lightweight one-stage training pipeline, SPLADE-Code achieves state-of-the-art performance among retrievers under 1B parameters (75.4 on MTEB Code) and competitive results at larger scales (79.0 with 8B). We show that learned expansion tokens are critical to bridge lexical and semantic matching, and provide a latency analysis showing that LSR enables sub-millisecond retrieval on a 1M-passage collection with little effectiveness loss. **Bio**: Simon is a third year PhD student at the University of Amsterdam, working on Information Retrieval and LLMs. He has graduated from a computer science engineering school in France, made an Erasmus exchange in London, during his master, at the imperial college london, and worked in the industry for 2 years at naver labs europe. Now he will present his latest work from an internship at naver labs europe. **Speaker #2:** Chuan Meng from University of Edinburgh **Title**: Revisiting Text Ranking in Deep Research **Abstract**: Deep research has emerged as an important task that aims to address hard queries through extensive open-web exploration. To tackle it, most prior work equips large language model (LLM)-based agents with opaque web search APIs, enabling agents to iteratively issue search queries, retrieve external evidence, and reason over it. Despite search's essential role in deep research, black-box web search APIs hinder systematic analysis of search components, leaving the behaviour of established text ranking methods in deep research largely unexplored. In this talk, we revisit key findings and best practices for text ranking methods in the deep research setting. In particular, we examine their effectiveness from three perspectives: (i) retrieval units (documents vs. passages), (ii) pipeline configurations (different retrievers, re-rankers, and re-ranking depths), and (iii) query characteristics (the mismatch between agent-issued queries and the training queries of text rankers). We perform experiments on BrowseComp-Plus, a recent deep research dataset with a fixed document corpus, evaluating a broad spectrum of text ranking methods across diverse setups. We find that agent-issued queries typically follow web-search-style syntax (e.g., quoted exact matches), favouring lexical, learned sparse, and multi-vector retrievers. Passage-level units are more efficient under limited context windows, and avoid the difficulties of document length normalisation in lexical retrieval. Re-ranking consistently improves performance, with deeper re-ranking depths amplifying gains. Translating agent-issued queries into natural-language questions significantly bridges the query mismatch and improves effectiveness. Related paper: [https://arxiv.org/pdf/2602.21456](https://arxiv.org/pdf/2602.21456) **Bio**: Chuan Meng is a postdoc at the University of Edinburgh, working with Dr. Jeff Dalton. He received his PhD from the University of Amsterdam in June 2025, supervised by Prof. Maarten de Rijke and Dr. Mohammad Aliannejadi. He was formerly an Applied Scientist Intern at Amazon. His research focuses on agentic information retrieval (IR) and deep research. He has published 25+ papers in top-tier venues such as SIGIR, ACL, EMNLP, NAACL, CIKM, AAAI, ECIR, and TOIS, with 650+ citations on Google Scholar and an h-index of 16. He has co-organised tutorials and workshops at SIGIR 2025, WSDM 2025, ECIR 2024–2026, SIGIR-AP 2024. **Counter:** SEA Talks #303 and #304.

* We **start at 11:30** at Train Station Driebergen-Zeist (in front of: NS Stationshuiskamer https://maps.app.goo.gl/rxbgbhe877qTaoE2A * Length: \~16 km (4 - 5 hr hiking) * What to bring: lunch, water, snack. * For whom: As always, sporty folks that like to combine social event with being active in nature. **Getting there by Train:** * To Station: Driebergen-Zeist https://maps.app.goo.gl/1o211iUUR7ZzWZAq8 **Getting there by Car:** * P+R Driebergen-Zeist: Stationsweg 15B, Driebergen-Rijsenburg (payed) https://maps.app.goo.gl/Rzkus3PV1cXaiBV89 **Note:** * Please **pay a small fee (3 euro)** to help us cover the (increased) yearly Meetup contribution of 240 euro. We'll ask you to pay before the start of the hike (can be on the day itself). No refunds, but in the unlikely event that hike would be cancelled and you already paid, you don't need to pay for your next hike. Thank you so much! Use the **safe link** here: https://betaalverzoek.rabobank.nl/betaalverzoek/?id=cqlYWv_MTpSjp2VkROXWhA * Keep in mind that the hike can be canceled when the weather is very bad (**always check the event before you go**). * If you RSVP 'yes' we expect you to show-up. Please do not cancel less than 24 hours before the hike. **No-shows** will lead to your removal from the group. Thanks for the understanding. * By signing up for this event, you agree to release the organizers from any responsibility and liability in all claims. As the participation is strictly voluntary and you freely choose to join, it is the responsibility of individuals participating to ensure that they are fit enough and have adequate coverage to protect themselves.

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This is a public event. https://www.nesko.nl Please WhatsApp your meetup organisor for your confirmation!

🥂 Skip koningsnacht en kom zingen! 🥂

**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** GitHub Copilot is powerful, but what if you could scale from a solo AI assistant to an entire team of specialized agents working in parallel? This session introduces Squad: an open-source framework for multi-agent orchestration that lets you define teams of AI agents with specific roles, responsibilities, and expertise. We'll progress from Copilot basics to the Copilot CLI, explore how Agents add autonomy, and see how Instructions and Skills let you customize agent behavior. Then, the climax: a live demo where a Squad team of 3 agents (Lead, Developer, Tester) stands up and builds a working application in real-time, showcasing true multi-agent collaboration. Whether you're new to AI or exploring how to scale your use of Copilot, this session will show you what's possible when agents work as a team. **YouTube Link** TBD

Columbus Code & Coffee is an inclusive, informal co-working session. People of all skill levels attend, and we love it that way. Many people (optionally) bring projects to work on, and many other people (optionally) socialize the entire time. It's entirely up to you! **What to Expect at the Intro Circle** \~\~\~\~\~\~\~\~\~\~\~\~\~ Near the beginning of the event (1:30 pm), we do a standup: * Organizer announcements, updates, and logistics Round 1 - (7 secs max): * Your name * What you're working on * What you can help others with Round 2: * Community events you wanna plug. If none, that's cool too. Round 3: * Job opportunities you're hiring for OR announce that you are looking for one. If none, that's cool. After the introduction circle, everything is self-organized! Feel free to work alone, pair up, attend one of our workshops/presentations, or mingle!

Join us for **Ben Frain**'s talk ... Ben's book "Responsive Web Design With HTML5 and CSS" caught my attention (and should interest you as well). Find it here: [https://rwd.education/](https://rwd.education/) ***Bring your laptop and expect to write some (non-AI generated) code!*** Food and drinks will be available. **LOCATION:** 6515 Longshore Loop, Suite 300, Dublin, OH 43017 **FREE PARKING:** 6725 Longshore Street, Dublin, OH 43017

Topic to be announced. **CALL FOR SPEAKERS** Learn more: https://www.awscolumbus.com/get-involved/ **THANK YOU** *VEEAM* for hosting our meetup! To learn more about *Veeam*, please visit their website: https://www.veeam.com/ **DIRECTIONS** 8800 Lyra Dr #450 · Columbus, OH go to 4th floor. **Want to sponsor the pizza and/or bar tab?** Please contact me if you would like to sponsor this meetup's pizza and/or bar tab: angelo@mandato.com

**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** TBD **YouTube Link** TBD

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)

Columbus Code & Coffee is an inclusive, informal co-working session. People of all skill levels attend, and we love it that way. Many people (optionally) bring projects to work on, and many other people (optionally) socialize the entire time. It's entirely up to you! **What to Expect at the Intro Circle** \~\~\~\~\~\~\~\~\~\~\~\~\~ Near the beginning of the event (1:30 pm), we do a standup: * Organizer announcements, updates, and logistics Round 1 - (7 secs max): * Your name * What you're working on * What you can help others with Round 2: * Community events you wanna plug. If none, that's cool too. Round 3: * Job opportunities you're hiring for OR announce that you are looking for one. If none, that's cool. After the introduction circle, everything is self-organized! Feel free to work alone, pair up, attend one of our workshops/presentations, or mingle!