C#

After hopping across various Berlin venues, we’re thrilled to return to Saftladen for the second edition of *Level Up Your Folds*! Big shoutout to this non-profit (and a very *professional* one, mind you 🍊) indie game developer collective for hosting us again – couldn’t ask for a better creative playground! 👾 Food or snacks for sharing during the origami session are very welcome, so bring them on! Here's an overview of what you could expect: * **Special format of 2x presentation** by our beloved origami masters, followed by **guided collective folding of a model** of their choice! * **Mandatory donation** (amount of your choice) – this supports essential costs like the Meetup subscription and keeps our community thriving 🌱 You can either submit a **physical donation** to the event host in person or make a **digital donation** **[here](https://paypal.me/origamiberlin?locale.x=de_DE&country.x=DE)** (and inform the host afterwards). * In-person folding practice for all levels – beginners and experienced folders are equally welcome. * Origami paper + model instructions will be provided (from the host’s collection, for reference only). Feel free to bring your own favorite sheets or tools! * Photos may be taken for memories & our archive (Meetup, Instagram, Telegram) – let the host know if you prefer not to appear. * **We kindly encourage everyone to buy at least one drink (€2 each) to support [Saftladen](https://saftladen.berlin/) for hosting us!** ⚠️ **RSVP Policy – Please Read** ⚠️ Our community has grown a lot since its birth in August 2024, which is amazing — but it also means we need to handle RSVPs more carefully: * RSVP opens **7 days before** each event (apart from short-notice events) and closes at **noon on the event day**. * Please cancel your spot or contact the host directly (via Meetup message function or our [Telegram channel](https://t.me/+T4URs80l2ig3NWNi)) by **noon on the event day** if you can't make it last minute. * Members with **2 no-shows** (without notice) will be removed from the group unless a valid reason is provided. Thank you for helping us keep our community respectful, reliable, and fun! 🙏 Get in touch if you have questions anytime and see you all at the folding tables very soon! 👾🍊

Bachata (the dance of our generation) is a social couple dance like Salsa - no choreography. The community in Berlin is active daily - you will meet a lot of open-minded people and make new friends quickly! Every Monday we have Bachata dance classes in Berlin - we are usually a group of around 20 people (95% beginners): 🕖 19:00 class: Beginners-+ Bachata Technique (0-1+ years experience) • No partner needed - we switch (for couples: partner rotation is optional). • You can start from zero in any of these classes! 📍 Adress: Jakob-Mierscheid-Steg ([Google Maps Link](https://maps.app.goo.gl/pjXopSSqAt55FQGW9)) - near S+U Hauptbahnhof We are down by the river. • Price: 12€ per class (10er-card = 100€). ✅ Dance teacher contact: [WhatsApp-group](https://chat.whatsapp.com/IWKPsid0cBDAUHCWKZNL2B) / [Instagram](https://instagram.com/mahir.bachata.berlin) 🇩🇪: Bachata (der Tanz unserer Generation) ist ein sozialer Paartanz wie Salsa - keine Choreographie. Die Bachata-Szene in Berlin ist groß und täglich aktiv - du wirst schnell viele offene Leute kennenlernen und neue Freundschaften schließen! Jeden Montag findet dieser Bachata Tanzkurs statt - wir sind meistens eine Gruppe von 20+ Leuten (95% Anfänger): 🕖 19 Uhr Kurs: Anfänger-+ Bachata Technik (0-1+ Jahre Erfahrung) • Kein Partner nötig - wir wechseln (für Paare ist der Partner-Wechsel optional). • Du kannst in diesen Kursen jederzeit von null starten! 📍 Adresse: Jakob-Mierscheid-Steg ([Google Maps Link](https://maps.app.goo.gl/pjXopSSqAt55FQGW9)) - Nähe S+U Hauptbahnhof Wir sind unten am Wasser. • Preis: 12€ je Kurs (10er-Karte = 100€). ✅ Tanzlehrer Kontakt: [WhatsApp-Gruppe](https://chat.whatsapp.com/IWKPsid0cBDAUHCWKZNL2B) / [Instagram](https://instagram.com/mahir.bachata.berlin) Schreib uns gerne eine Nachricht, wenn du offene Fragen hast! Wir freuen uns auf dich ❤ Bachata Classes Berlin

-DROP IN - *(English below)* **Lindy Hop \| Swing Dance** Klassen (fast jeden Montag) 19:00 Uhr Starter 20:15 Uhr Improver / Refresher Für mehr Informationen & Kosten, bitte hier schauen: [SWING PATROL KOLLE 37](https://www.swingpatrolberlin.com/sp-kolle37.html) \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\- Classes (almost) every Monday 19:00 Uhr Starter 20:15 Uhr Improver / Refresher For more information & cost, please look here: [SWING PATROL KOLLE 37](https://www.swingpatrolberlin.com/sp-kolle37.html)

📢 WICHTIG 📢 Diesmal organisieren wir das Treffen draußen, im Tilla-Durieux-Park gegenüber The Playce in Potsdamer Platz. Wir sitzen auf dem Gras, wo der Boden flach ist. Wenn möglich bring bitte Picknickdecken mit.

Andere drücken die Schulbank, wir aber wollen in gemütlicher (und realer) Atmosphäre wieder aufeinandertreffen und einen Deutsch-Spanisch-Tandemkurs aufleben lassen. Beim einfachen Zusammenkommen und kennenlernen lässt es sich schließlich viel effektiver lernen. und Spaß haben. ...

**\*\*This event has been free for over three years, but only due to the support of anonymous donations behind the scenes. Please consider [donating via Eventbrite](https://www.eventbrite.de/e/read-wedding-a-berlin-open-mic-for-poetry-storytelling-tickets-1975773081473?aff=oddtdtcreator) if you are able, to help this stay free for everyone else.** -- Whether you're poetry-curious or a seasoned performer, join us for our monthly open mic night at Hank Chinaski! This event is brought to you, for free\*\*, by the [Re(a)d VVedding Collective](https://www.instagram.com/readwedding/), who organize regular events for all phases of the writer's journey, all in the northern Kiez(es) of Berlin. Join us for our core event which has been going on in Wedding for over three years. You are most welcome to share your work (or that of writers you admire) & meet fellow enthusiasts through this event. All written works & languages are welcome, though bigotry, racism, transphobia, Islamophobia, antisemitism (which *is not Anti-Zionism*), and so on are not welcome in this space. **Format - 3 sections:** * Sections 1 & 2: ≈12 performers (≈6 per section, kicking off at 19:30) * Section 3: Around 21:30, we'll hold space for a writing session and optional sharing afterwards. This open mic is not only about already “finished“ work! For the readings, priority is first given to those who haven't read earlier in the evening & especially to first-time readers! **\*\*Donation​s:** * While our open mic will always be free, we do happily accept donations [via Eventbrite](https://www.eventbrite.de/e/read-wedding-berlin-open-mic-for-poetry-storytelling-tickets-670852075617?aff=oddtdtcreator) or at the door. * Donations do not guarantee a reading slot, but help support us in putting in this event, others around Wedding, Pankow and Moabit, and our ongoing zine publications. We appreciate it deeply and as a small collective, will put it to good use! **RSVPs​ & Sign Up:** * RSVP via Meetup, Eventbrite, or just show up. Online RSVPs DO NOT save performance spots * Sign up at the door between 19:00-19:30 * 5-minute performance slots. Please respect this limit to avoid cutting off your work Experience the magic of live storytelling and poetry with us!

🇬🇧 **Japanese Language Kaiwa! #9** Hi guys, unfortunately I had to cancel the other event. I originally planned it for Saturday the 23rd, but I accidentally set the event for the wrong week, and next Saturday I won’t be available. So I’d like to try having it on Monday the 25th instead, since it’s a holiday. I know it’s super short notice, but I still wanted to give it a try. It’ll probably be a small group, but that’s ok. The rest stays the same: Meeting point at **Mauerpark**, starting at **4:00 pm.** Feel free to bring picnic blankets, drinks or snacks for yourself, or something to share with the group. Apologies for the confusion, and hopefully see you there! Mauro ーーーー 🇯🇵 **日本語会話会 Kaiwa! #9** みなさん、こんにちは！ 残念ながら前回のイベントはキャンセルすることになってしまいました。もともとは5月23日（土）に開催する予定だったのですが、間違えて別の週でイベントを作成してしまい、その日は参加できなくなってしまいました。 なので、祝日でもある5月25日（月）に開催してみようと思います。 かなり直前のお知らせになってしまいましたが、それでもやってみたいと思いました。たぶん少人数になると思いますが、それもそれでいいかなと思っています。 他の内容はそのままです！ 集合場所は**Mauerpark**、**16時**スタートです。 ピクニックシートや飲み物、お菓子など、自分用でもシェア用でも自由に持ってきてください。 混乱させてしまってすみません。 もし来られたら、ぜひ会いましょう！

The next **Berlin C++ Meetup** hosted by think-cell takes place on **Tuesday, May 26**. Join us for an evening with the Berlin C++ community! This meetup is a chance to step away from your day to day work, meet other developers, exchange ideas, and have real conversations about modern C++ in a relaxed setting. \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\- ## **Talk** ### **Contract assertions on virtual functions** *Timur Doumler – Citadel Securities* Contracts assertions were introduced in C++26, but they cannot be applied to virtual functions. To close this gap, we first need to answer the question: how should contracts assertions behave in the presence of inheritance and runtime polymorphism? In this talk, Timur explores why this problem is harder than it looks. He reviews existing approaches from other languages, such as Eiffel, D, and Ada, highlights why they don’t fully translate to C++, and outlines the key design challenges involved. He then presents a concrete proposal for how contract assertions on virtual functions could work in C++, balancing correctness, safety, and usability. Along the way, the talk touches on good API design, the true meaning of the Liskov substitution principle, and how to reason about program correctness. \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\- 📅 **Date & Time:** Tuesday, May 26, 2026 – 18:30–21:30 📍 **Location:** Le Wagon Coding Bootcamp, Rudi-Dutschke-Straße 26, 10969 Berlin 🕒 **Agenda** 18:30 – Doors open 19:00 – Talk + Q&A 20:40 – Pizza, Drinks and Networking \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\- **RSVP now to save your seat!**

**The TypeScript Berlin meetup is back!** After a long break, we're reviving the meetups for 2026 and we'd love to see you there. Whether you've joined us before or you're coming for the first time, welcome! Come round for talks, snacks, good conversations, and a chance to connect with other TypeScript devs in Berlin. *** **🎙️ Interested in speaking?** We have an ongoing call for speakers for this event as well as future ones. [Fill it out here](https://tally.so/r/jaGa1J). *** **📅 Schedule** * 18:30 - Doors open, drinks and snacks 🍕 * 19:00 – Welcome 🤝 * 19:05 - Talk 1: TBC 🎙 * 19:35 - Talk 2: TBC 🎙 * 20:05 - Break 🥤 * 20:20 - Talk 3: TBC 🎙 * 20:50 - Wrap-up * 21:00 - Doors close 👋 *** This meetup is organised by [Prisma](https://www.prisma.io/). By attending the event, you agree to abide by our [Code of Conduct](https://www.prisma.io/event-code-of-conduct). For questions, reach out to events@prisma.io

We are back in the c-base! Do you already run NixOS and want to talk to other people or want an introductory session with some NixOS users. Just bring your machine! Usually there are no topics, we just sit in front of our computers, talk about stuff, debug some problems or review some PRs on nixpkgs. There are drinks usually available from the c-base bar. If you can't find us. just ask around or ask in irc (#krebs on hackint)

**Build for Everyone — Accessibility for Mobile** Flutter Berlin is hosting a joint meetup with Kotlin User Group Berlin and CocoaHeads Berlin, focused on building accessible mobile apps. **Location:** Hedwig-Dohm-Haus, Berlin We’ll cover both strategy and hands-on implementation — from understanding platform differences (Android, iOS, cross-platform) to real-world accessibility pitfalls and live testing. With: **Important:** Registration is via Luma, not Meetup. Please register here: https://luma.com/xo7d3vb4

Every last Wednesday of the month (unless communicated differently here), you are invited to join the Game Night @ C\*SPACE Berlin, to have fun, relax, and meet new people! Our co-working space member at C\*SPACE, Miguel, together with Carlos, will be hosting the Community Game Room, bringing new games every month for you to discover or rediscover. Between the 2 of them, they have more than 300 games in their collections so there will be something for everyone. You are also more than welcome to bring along your favorite games! **Entry:** Free, but we do ask for a donation for drinks available in the kitchen (coffee, tea, beer, etc.). **About our hosts:** **Miguel** is a professional venture capitalist by day and amateur game designer by night. He has a wide ranging interest in tabletop games including word games, social deduction party games, economic Eurogames (favorite designers are Martin Wallace and Uwe Rosenberg!), historical wargames and card games like Bridge, Poker and the German classic, Skat. **Carlos** is a mathematician who marvels at the art and science of designing board games , and greatly enjoys playing in a group (particularly cooperative games!). If you have questions about the event, don't hesitate to reach out to Miguel on Whatsapp or Signal at +491623965924.

While we are approaching the middle of the year and KotlinConf is just over - we are thrilled that Trade Republic hosts us again! So mark the date! **Line-Up:** 👉 **Lists, Sequences, and Flows: Scaling Data Processing in Kotlin without Melting Your Memory.** *by Daniela Valero* In this talk, Daniela shares her journey of meeting a major backend deadline while managing a data pipeline's memory footprint. You’ll learn how to transition from eager List operations to lazy Kotlin Sequences and jOOQ Streams (using database fetchSize chunking) to keep memory usage flat. Finally, we’ll explore using Kotlin Coroutines and Flow to introduce safe concurrency so your data processes quickly without straining your database. 👉 **The show must go on** *by Blagoja "Baki" Stamatovski* **👉 TBD** **Speaker Bios:** 🗣 **TDB**

Welcome to our cosy Godot Engine Community Meetup! This is not a structured meeting, but rather a friendly get-together. We will hang out, chat and maybe show some of our current projects! 🦜 Regardless if you are an artist, designer, programmer, beginner, hobbyist, professional or anything in between: join us for sharing knowledge, creating art together, coding together, joining game jams together and having fun! 🌼 This meetup will happen at [Saftladen Game Collective](https://saftladen.berlin), Normannenstraße 1-2, 10367 Berlin-Lichtenberg. 🌳 You can also join us on [our Discord Server](https://discord.gg/Sm3CgrqqQa). ☎️ Follow us on [Mastodon](https://mastodon.gamedev.place/@GodotUserGroupBerlin) for updates. 📢 Also check out [our website](https://godot.berlin). 🌐 Please be [excellent to each other](https://godotengine.org/code-of-conduct/)! 🕊️

**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** Like it or not, AI agents are now capable of turning a quickly written paragraph of requirements into a pull request that is ready to be integrated into real-world production applications and it's now our responsibility to make sure AI doesn't go rogue and take down prod - or corrupt our data by misunderstanding the requirements or our existing schemas. In this session we'll explore strategies to protect our codebases through unit and integration testing, documentation, and code review along with additional ways of providing context and guard rails to our AI agents as they carry out the work we've assigned them to do. By the time we're done, you'll have a firm grasp of the problem and understand some helpful options for protecting your codebase from vibe coding mishaps getting YOLOed into prod. **YouTube Link** TBD

Bring your work or your hobby, hang out, and code with us. Follow @buckeyecocoa for more information.

Come out to Improving for our monthly iOS and Mac meetings. This Month's Presentation: Nothing yet. (You should volunteer). What is Cocoaheads (http://cocoaheads.org/)? CocoaHeads is a group devoted to discussion of Apple Computer's Cocoa Framework for programming on MacOS X and iOS (including the iPhone, iPad and Apple Watch). During monthly meetings, members present on their projects and offer tutorials on various programming topics. What is BuckeyeCocoa (http://buckeyecocoa.org/)? BuckeyeCocoa is a group of Objective-C/Swift developers/enthusiasts. We host monthly Cocoaheads and near-weekly NSCoder meetings in Columbus, Ohio. The meetings are free to attend. Presentations! Presenters welcome! We are always in need of people willing to present material. Any Swift and/or Objective-C related topic is welcome. Times can be 5 minutes (i.e. lightning talks) to a maximum of 2 hours. Interested? Contact info is on the BuckeyeCocoa website. To volunteer for a presentation contact us at @BuckeyeCocoa on Twitter. Follow us on Twitter! @BuckeyeCocoa (https://twitter.com/#!/Buckeyecocoa/) For more information: http://buckeyecocoa.org/

PLEASE NOTE!!! This event will be In-Person for our very 1st Improving collab! If you know the [Columbus Unity group](https://www.meetup.com/columbus-unity-user-group/) location, we'll be at the same place. This is our 1st event and are doing a soft launch with limited attendance. 1st come 1st serve. If you want to be there and we fill up, please email me at [info@thecogg.com](mailto:info@thecogg.com) and I'll be in touch. All street parking is free on Sundays but you can also pay to park in any of the local garages. See image of [parking map here](https://drive.google.com/file/d/1Mr9_LFIggbs-0_Zd3AJTGNqEhgMf2TzQ/view?usp=sharing). \-\-\- On the last Sunday of the month, we're having our usual end-of-the-month social gathering with our GameDev Meetup meeting. There will be announcements and presentations followed by some social networking Let's continue the conversations with good vibes and friends. All are welcomed from all ages and backgrounds to this public event. If we can, we'll be streaming or uploading the video later via our COGG YouTube channel here: [https://www.youtube.com/@TheCOGG/streams](https://www.youtube.com/@TheCOGG/streams) (Also please do subscribe if you have not done so!) No game development experience required! If you are interested in doing a 20 minute game development related presentation, please fill out our form online here: [https://goo.gl/forms/lVdTJZiNJewlPJuj1](https://goo.gl/forms/lVdTJZiNJewlPJuj1) Or e-mail us at info@thecogg.com with the following: Your Name, Company/Affiliation, Name of Your Game/Topic, Description, Tech Needs, and Your Contact. Be sure to check out our Discord for real time news updates: [https://discord.gg/NrBhuNQ](https://discord.gg/NrBhuNQ)

Our monthly PHP meetup. A virtual shindig courtesy of Zoom. Check back here for the details around 6:15 pm

**Latest Dojo Location!** **Knotty Pine Brewing** 1765 W 3rd Ave, Columbus, OH 43212 We're going to try a new dojo location for a few weeks and see how it works Dojos are informal Python group study sessions where everyone interested in Python gathers to learn about Python, help others with Python, or just hang out. Everyone is welcome from Python beginners to experts. Bringing a laptop is encouraged (we'll have extension cords and power strips). If there's something you want to learn leave a comment on this invite so we can plan ahead. We're looking for speakers for our Monthly Meetups! Fill out the form if you are interested in presenting to the Python Community. https://forms.gle/ehSfUAC2WgR34Crq9