Smalltalk

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!**

Erlerne Meditations- und Entspannungsverfahren kennen und sorge damit für mehr Bewusstheit und Stressreduktion in deinem Alltag.

BHNT #112: the fifth BHNT in 2026. The title is inspired by the issues around Bambulab (Boo). Your hacks do not have to be connected to the title (bonus points if they do though) Please RSVP and bring your hacks! There are 8 dynamically allocated Slots that consist of 5min presentation + 5min conversation with the audience. To refresh your memories or get familiar with the concept - see some old hacks here: [https://bhnt.c-base.org](https://bhnt.c-base.org/) Hope to see you - looking forward! [RSVP here](https://platform.openmeet.net/events/bhnt-112-bamboo-hacks-8zv0v)

Berlin is no longer so dark! Spring has come! 🌷 Let's catch those fresh new rays of sun ☀️. While walking together we can enjoy a nice conversation, get those steps in, increase our serotonin production as well as sync the circadian rhythm. I would like to invite you to our mental health walk event, for the first time - weekend format! 😎 Agenda: 18:00 We meet at Schöneberg Park next to the fountain with the golden deer statue ("Der goldene Hirsch"). 18:05 We walk to Volkspark Wilmersdorf 19:00 We arrive back in Schöneberg Park, at the golden deer statue. We walk at every weather, so make sure to dress properly! Looking forward to meeting you at our next walk! Marija Please note\*\*:\*\* This gathering is meant for connection and conversation, and is not a replacement for therapy or professional mental health support.

## Learn Go and NixOS deployments with large language models Hello, 世界! When used sensibly, language models can be tutors, too. For meetup #60 on Tuesday [May 26, 2026 19:00 CET](https://www.meetup.com/leipzig-golang/events/312537727) we are really happy to have [Maxime](https://www.linkedin.com/in/plumps/) dive into Nix/NixOS with the help of language models. Nix is a functional package manager and its immutable traits enable robust, reproducable deployments of Go (and other) projects. The high level goals of Nix/NixOS are similar to other immutable Linux distributions, like [Silverblue](https://fedoraproject.org/silverblue/) or [Bazzite](https://bazzite.gg/). Becoming familiar with the Nix configuration language can be a challenge, but one that a well instructed tutor may help with. > Artificial intelligence techniques are increasingly used in education to enable personalized learning and intelligent tutoring [LLM Agents for Education: Advances and Applications](https://aclanthology.org/anthology-files/anthology-files/pdf/findings/2025.findings-emnlp.743.pdf) (11/2025) Why reproducible and immutable deployments play a role? [Justin Garrison](https://justingarrison.com/blog/state-of-immutable-linux/) says: > It’s 2026, if you’re not using something immutable (or at least reproducable) you’re doing more maintenance work than you should. [blog post recapping talk from [Southern California Linux Expo 23x](https://www.socallinuxexpo.org/scale/23x)], 03/2026, PASADENA, CA ### Schedule * 18:45 Doors open * 19:00 Welcome * 19:10 Dive into Nix/NixOS with LLMs * 19:50 Open discussion We’ll meet: * in person at [Basislager Leipzig](https://basislager.co), at [Peterssteinweg 14, 04107 Leipzig](https://maps.app.goo.gl/1fMkeDSPZ7Aauszh8) ([OSM](https://www.openstreetmap.org/node/3504864558)) * and online via [Google Meet](https://meet.google.com/poy-koue-spc) Join us to discuss robust Go deployments, language models as learning tools and more!

Schnapp dir dein Lieblingsgetränk, mach eine kurze Pause vom Alltag und lasst uns einfach entspannt ein paar neue Leute treffen, um dann wieder mit neuer Energie und neuen Perspektiven weiterzumachen :) Es wird ein Zoom Treffen sein! online. Bitte mit Kamera und Mikrofon :)

Teile deine Texte, erhalte Feedback, höre anderen zu. Kurzgeschichten, Gedichte, Essays – offener Abend für Lesende und Zuhörende. **Jeden vierten Dienstag des Monats um 20:00 Uhr in Berlin-Moabit** Einlass: 19:30 Uhr Leseabend Beginn: 20:00 Uhr **Über den Leseabend** In unserer Leseabend Textwerkstatt werden selbstverfasste Texte mit Gleichgesinnten geteilt. Ob Kurzgeschichte, Gedicht, Essay oder Roman-Auszug – hier findest du ein aufmerksames Publikum und bekommst konstruktives Feedback zu deinem Projekt. An diesem Abend wird nicht geschrieben, aber es gibt einen lebendigen Austausch über Sprache, Stil und Storytelling. Auch reine Zuhörer sind sehr herzlich willkommen. Teilnahme und Getränke auf Spendenbasis **Du möchtest vorlesen?** * Dein Text sollte unveröffentlicht und auf Deutsch sein * Maximale Lesezeit: 12 Minuten * Melde dich mit kurzer Beschreibung deines Projekts bei leseabend@textcollective.de (Spontananmeldungen sind je nach Kapazität möglich, können aber nicht garantiert werden)

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**

**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

**Relax. Connect. Create. ☕** After a full week of work, meetings, study sessions and life in fast-forward, it’s time to slow down. Join us this Saturday afternoon in Berlin for a relaxed coffee hang-out where this week's agenda is good company & warm drinks. You're also invited to bring some boardgames, drawing/coloring materials (I will bring an adult coloring book) **What’s the plan?** We’ll meet in a cosy spot, draw, chat about everything and nothing, swap stories and simply enjoy the moment. No pressure. No formalities. Just a bunch of friendly people sharing a Saturday coffee. **Who’s welcome?** Everyone! Whether you’re a Berliner born and raised, newly arrived in the city, from Germany or abroad, if you like meeting open-minded folks and spending some relaxed time—come join us. **When & how?** Saturday afternoon. Detailed time and place in our Telegram group. ➡️ Join us on Telegram: [https://t.me/berlinsaturdaycoffee](https://t.me/berlinsaturdaycoffee) Hop in, say hello, and we’ll share the final details. **Why join?** *Because you deserve a break. - Because you enjoy being creative. *Because you enjoy boardgames - Because meeting new people sparks fresh energy. *Because coffee tastes even better when shared. - Because Saturday afternoons were made for this. Respect and Safety: There is always at least one organizer present at every meetup. If you ever feel unsafe or bothered by someone’s behavior, you can reach out to an organizer privately. Your identity will remain confidential, your concern will be taken seriously, and no inappropriate behavior is tolerated — anyone making others feel uncomfortable will be removed from the group immediately. We hope to see you there. Bring yourself, your smile, drawing materials, your stories—or just your comfy self. Let’s make Saturday a little more laid-back, a little more social and a lot more nice. See you soon! —Your Saturday Creative Coffee Crew ☕

**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

**Rust Berlin Talks** is back for another evening of talks, shared ideas, and networking. Join us to learn, share, ask, and connect. If you work with Rust professionally, use it in side projects, contribute to open source, or are simply curious to learn more, you are very welcome. **Agenda** * Doors open: 18:30 * Start: 19:00 * Talks * Open mic / lightning talks * Networking **Speakers** Egor Lebedev - Welcome and a short note from the RustRover team Wolf Vollprecht - Pixi - A cross-platform package manager written in Rust One more speaker - To be announced soon **Speaker Bios** Wolf Vollprecht is the founder and CEO of prefix.dev, where he builds open-source software supply chain infrastructure for the conda ecosystems. Core projects include Pixi (a cross-platform package manager written in Rust), rattler (crates to work with Conda packages), and rattler-build. With \~7 years in the conda ecosystem, including creating Mamba during his time at QuantStack, Wolf has a lot of experience in making package management fast, reproducible, and secure. **Open mic & future talks** We’ll reserve a few short slots for anyone who wants to share something with the group. This can be a quick idea, a project, or an experience. Slides are optional. If you’re interested in giving a longer talk at a future meetup, this is also a good opportunity to connect with the organizers. **Venue & access** Please arrive on time. We will have someone at the entrance to let people in between 18:30 and 19:15. After that, access becomes more difficult as the doors are locked and require manual opening. **Registration** The venue has limited capacity and events typically fill up with a waiting list. If you register and can no longer attend, even at short notice, please un-RSVP so someone else can take your spot. Looking forward to seeing you all!

Welcome to the PyData Berlin May meetup! We would like to welcome you all starting from 18:00. There will be food and drinks. The talks begin around 18.30 and the doors will close at 18:45. **Make sure to arrive on time!** Please provide your first and last name for the registration because this is required for the venue's entry policy. If you cannot attend, please cancel your spot so others are able to join as the space is limited. **Host**: **GetYourGuide** is excited to welcome you to this month's version of PyData. \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* The Lineup for the evening **Talk 1: Text2SQL in the Wild — Agentic Workflows & Semantic Models on Customer Data** **Abstract**: Translating a business user's natural language question into a reliable SQL query has huge value for business analysts, but doing it accurately at scale, on messy enterprise data, for complex queries, is incredibly difficult. This talk walks through a production Text2SQL system built on four pillars: semantic models built on customer data, RAG-based semantic search, an agentic verification and correction loop for building the SQL, and an evaluation framework for the entire process. Raw schema information is not enough for text2sql to work. Rather, thorough documentation including business metrics, synonyms, and qualified example queries, are required. We'll cover how to automate this documentation pipeline by mining query logs, generating descriptions with LLMs, and organizing everything into a knowledge graph and vector search index. From there, we'll dive into the agentic flow that takes a user question and iteratively generates, validates, and fixes SQL against a live database. The agentic framework analyses syntax errors and execution results to help it fix the SQL. Participants will leave with practical takeaways on RAG architecture for structured data, agentic retry patterns, and how to think about evaluation for Text2SQL systems in production. **Speaker**: Oren Matar **Bio**: Oren Matar is a principal data scientist and algorithms developer, with a background in social sciences and Bayesian methods. He specializes in NLP and time series forecasting, as well as agentic methods for data retrieval and processing. **Talk 2: Interpreting and Communicating Statistical Models** **Abstract**: Extracting actionable insights from complex statistical models remains a challenge, as raw coefficients are often uninterpretable due to nonlinearity, interactions, or hierarchical structures. This talk introduces a unified framework for model interpretation based on the principles of the Marginal Effects project ([https://marginaleffects.com/](https://marginaleffects.com/)). We move away from internal model parameters toward quantities of interest, such as marginal effects and adjusted predictions that translate statistical output into the "natural language" of the data. We will demonstrate these concepts in Python using the Bambi interpret module, showcasing a seamless workflow for interpreting Bayesian models built on PyMC. The audience will learn how to use the four primary interpretative pillars: Predictions, Comparisons, Slopes, and Marginal Means to compute average marginal effects and visualize conditional relationships. By the end of this session, you will be equipped to turn sophisticated GLMs and multi-level models into clear, rigorous narratives that are easily communicated to stakeholders. **Speaker**: Juan Orduz **Bio**: Juan is a Mathematician (Ph.D. Humboldt Universität zu Berlin) and Principal Data Scientist at PyMC Labs. He is interested in interdisciplinary applications of mathematical methods. In particular, time series analysis, Bayesian methods, and causal inference. **Lightning talks** There will be slots for 2-3 Lightning Talks (3-5 Minutes for each) between the two main talks. Kindly let us know if you would like to present something :) \*\*\* NumFOCUS **Code of Conduct** THE SHORT VERSION Be kind to others. Do not insult or put down others. Behave professionally. Remember that harassment and sexist, racist, or exclusionary jokes are not appropriate for NumFOCUS. All communication should be appropriate for a professional audience including people of many different backgrounds. Sexual language and imagery are not appropriate. NumFOCUS is dedicated to providing a harassment-free community for everyone, regardless of gender, sexual orientation, gender identity, and expression, disability, physical appearance, body size, race, or religion. We do not tolerate harassment of community members in any form. Thank you for helping make this a welcoming, friendly community for all. If you haven't yet, please read the detailed version here: https://numfocus.org/code-of-conduct \*\*\*

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/)! 🕊️

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/

The Alliance is part of the Greater Central Ohio Chapter of the Barbershop Harmony Society. We are an all-voices chorus dedicated to providing an inclusive environment for all those who love to sing, regardless of their race, gender identity, sexual orientation or musical background. The Alliance is the first and only all-voices barbershop chorus in Central Ohio. **Who:** Anyone with a passion for singing at a high level. Previous barbershop chorus/quartet experience not required. **When:** The Alliance rehearses weekly on Thursdays from 7pm-10pm. **Where:** Lord Of Life Lutheran Church: 2480 W Dublin Granville Rd, Columbus, OH 43235 To become a full member of The Alliance, we welcome you to start by visiting us for a few rehearsals to experience the group and sing with us! Then, you may begin the 2-part audition process for membership: the assessement, and audition. We strive to make our auditions as stress-free as possible to help you let your best singing self shine.

**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

Ciao a tutt\*! Let's meet Monday at 6.30pm at the Upper Arlington Library (**Tremont** Branch) in **Meeting Room A** to speak in Italian for 1 hour.

**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