Geeks & Nerds

The longest day of the year is comming and let's another Kotlin meetup. This time we geather at N26! **⚠️⚠️⚠️ Due to a venue policy please submit the following form for additional details. Without it, you won't be allowed inside the venue:** https://forms.gle/XjqVXkD3FARCM6jA8 **Line-Up:** 👉 **TestBalloon: Kotlin testing is easier (and more fun) than you think** *by Oliver Okrongli* You want an easier way to write tests? Parameterize tests in plain Kotlin? Reuse a series of tests? Easily extend own your test setup? Have first-class support on all platforms? All without struggling with a huge framework API? TestBalloon is a new test framework that brings the power of Kotlin to your test setup. With a small-surface API, a hierarchical test structure and an extensible DSL, TestBalloon makes Kotlin testing easy, even at scale. Oliver, the author of TestBalloon, will show testing patterns and strategies and lots of practical examples, ranging from simple unit tests with less boilerplate to advanced testing with coroutines and generated data. This talk is based on insights first presented at KotlinConf 2026 in Munich. At the end of this talk, you’ll be able to firmly the answer the question: "How can I master Kotlin testing with ease, and make my team release with joy and confidence, every time?" 👉 **One Topic to Rule 'Em All** *by Yonatan Karp-Rudin* Kafka delivered every event exactly once, in order, and lost nothing. So what broke? This talk follows that question into the gap most event-driven systems leave open: what actually guarantees the order your domain depends on, and what quietly doesn't. We start from a real log line, find the crack in an architecture that looks clean and ships fast, and rule out the fix everyone reaches for first. The cure turns out to be one sentence of domain thinking plus one line of config, though the Schema Registry will fight you on the way there. A live demo runs the bug and the fix back to back: same load, same hero, one change. If you build with Kafka, you have probably shipped a version of this bug. You will leave able to spot it and fix it before it pages someone. 👉 **He Who Must Not Be Migrated** *by Nicola Corti* **Speaker Bios:** 🗣 Oliver Okrongli Oliver has been shaping and creating software from backend to frontends. He is the author of TestBalloon, a next-generation Kotlin test framework. Before, he has helped to maintain Kotest, and contributed to several libraries of the Kotlin ecosystem as well as the Kotlin compiler. Can be found on GitHub (OliverO2) and the kotlinlang Slack (Oliver O). When not developing, he is most probably in deep talks, dancing, snowboarding or F18 catamaran sailing whenever he gets a chance. 🗣 Yonatan Karp-Rudin Yonatan Karp-Rudin is a Staff Engineer at Billie, building event-driven systems in Kotlin and Spring Boot. Off the clock, he plays with AI agents and builds random tooling, trying to hand off as much of his own workflow to a machine as he can. The rest of the time he's brewing mead or deep in a video game. **🗣 TBD**

Inner Landscape is an art experience that invites you to partecipate actively in your own inner exploration through image-making. You Inner World- feelings, thoughts, images and ideas- is the primary material. We do not create art to make it beautiful . We create art to discover something true. This is a form of dynamic therapy, requiring one to partecipate in one’s own treatment- as a creator , an Inner Guide. Through the wet-on wet watercolour technique, we work with the paradox of control and surrender: you place water on the paper, and then the paint moves where it will. In this place between intention and accident , something honest often appears . It is messy, playfull and real. No artist experience is required, come as you are:). Important Logistics: Please confirm your partecipation, small group. 25 euro pro Person. All materials are provided Great Playlist 🔥

We are happy to invite you to our next iOS meetup. This time we cooperate with the amazing 42 Berlin to share the knowledge and experience in iOS development. 18:00 Doors open 18:30 Welcome on campus **18:45** **— Sebastian Hagedorn, director of Engineering at Clue, presents "The Sensitive App".** Is your app really working, or just not crashing? “The Sensitive App” reports subtle bugs regardless of origin, and validates your assumptions in production so you don’t have to resort to guessing or praying. Learn how to turn your app into the first line of defense for your entire system’s health! **19:45** **— Dmitry Kurkin, lead Mobile Engineer at SuperNext, presents "Lessons that iOS Native Project could learn from ReactNative in agentic development".** We'll inspect the components of the React Native engine that provide faster feedback and boost agentic iterations.

**Hula 'Olapa Training zum Kennenlernen** **donnerstags** **in Kreuzberg-Neuköln, online + in Präsenz** **Di 11.06.-02.07.26,** **18:00-19:00, 4 Termine, 68 €** Jetzt buchen und dabei sein! Du lernst das Hula 'Olapa Training kennen! Hula kommt ursprünglich aus Hawaii. Im Hula lernst Du Schrittbewegungen in Kombination mit symbolischen Gesten kennen, die eine Geschichte erzählen aus dem Leben Hawaiis, von den Menscchen, den hawaiianischen König\*innen und Königen, von der Natur der pazifischen Inseln, den Vulkanen, dem Ozean und dem Wind. Da Hula in den Kampfkünsten gründet, schult Hula 'Olapa Fitness, Konzentration mit erzählendem Tanz. Die Gelegenheit jetzt im Sommer einzusteigen. Der Kurs im Juni ist ein kürzerer Trainings-Block von 4 Terminen. Der Kurs findet donnerstags als Teil des fortlaufenden Hula 'Olapa Trainings für Anfänger mit der 'Ulugruppe statt. Du lernst die fortlaufende Anfänger\*innengruppe kennen. Das Training läuft in Präsenz und online für überregional teilnehmende Schüler\*innen. The hula 'olapa training is open to english speakers. Please contact us for further information: [info@hula-makahikina.de](mailto:info@hula-makahikina.de) **Location: Tanzstudio Chachachicas** **in Kreuzberg-Neuköln** Hasenheide 9, 2. HH., 10967 Berlin, U8/U7-Hermannplatz **Buchen, Booking:** Down below through paypal or via the hulaschool website - check out: "Hula zum Kennenlernen" und "Buchen" [Training buchen](https://www.hula-makahikina.de/trainingsangebot/training-buchen.html) Kontakt, contact: Kumu Monika Lilleike [info@hula-makahikina.de](mailto:info@hula-makahikina.de) [www.hula-makahikina.de](http://www.hula-makahikina.de/)

An *electric* atmosphere featuring visiting pros and some of the best comedians in Berlin at the city's longest-running weekly show. There's no such thing as a bad Chuckleheads; it's as consistent as it gets. Come and find out why we have more regulars than any comedy show in Berlin. The right mix of lively yet laid-back energy in an intimate setting, with well-curated line ups. Chuckleheads is primarily for experienced comedians, though depending on the week we might have a spot for a newbie or two. Doors: 8:00 pm Showtime: 8:30 pm RESERVATIONS ARE HIGHLY RECOMMENDED! We got limited seating. Book the amount of seats you need with your name and we'll have them ready for you. It is still a free-entry show, though please donate to keep the laughs coming and pay for production costs. Suggested donation is 10-20 euros. If you've been to other shows, you know it's well worth it. Come be part of it! As is tradition in the nine years (!) of the show, free shots are also given at the start of each show. Produced and hosted by Daniel Gutierrez. See you all Thursday!

**QUIZ #88.2 @ Bar Degendorff** GERMAN BELOW/DEUTSCH UNTENSTEHEND **Trivia Night – English & Deutsch** A fun, social trivia night for locals, expats, newcomers and long-time Berliners alike. The quiz is **open to everyone** and played **bilingually in English & German**. \#\#\# The quiz setup: 📅 **Thursday, 18th of June** 🕔 Doors open: 6:45 pm \| 🕡 Quiz starts: 7:30 pm 📍 **Location:** Bar Degendorff, Petersburger Str. 74a, 10249 Berlin 💰 **4 € per person** 👤 **Solo players welcome** or play as a team (max. **6 people**) 🤝 No team? We’ll match you with others at mixed tables ✍️ \*\*3 to 4 rounds à 10 questions (\*\*Topics include: music, picture riddles, pop culture, general knowledge & more) Languages: 🇬🇧 & 🇩🇪 🏆 **Prizes** for the top 3 teams + the legendary **Lucky Loser** **Good to know:** Most questions are designed to be broadly accessible. However, from time to time there *may* be questions related to **German history, culture, or German-speaking pop culture**. No need to be an expert though – **teamwork is key**, and mixed teams are very welcome. 📸 **Photos & promo:** We occasionally take photos during the event for promotional purposes (website & social media). If you prefer **not** to appear in photos, just let us know briefly during the event – no problem at all. Come solo, bring friends, or find a team on the spot – we’ll take care of the rest. See you there! 🧠✨ \*\*\* **Quizabend – Deutsch & Englisch** Ein geselliger Quizabend für Berliner:innen, Zugezogene, Expats und Quizfans aller Erfahrungslevel. Das Quiz ist **für alle offen** und wird **zweisprachig auf Deutsch & Englisch** gespielt. \#\#\# Die wichtigsten Infos: 📅 **Donnerstag, 18. Juni** 🕔 Einlass: 18:45 Uhr \| 🕡 Quizbeginn: 19:30 Uhr 📍 **Location:** Bar Degendorff, Petersburger Str. 74a, 10249 Berlin 💰 **4 € pro Person** 👤 **Solo-Anmeldung möglich** oder als Team (max. **6 Personen**) 🤝 Kein Team? Wir setzen euch an **Mixed Tables** zusammen ✍️ \*\*3 Runden à 10 Fragen (\*\*Themen: Musik, Bilderrätsel, Popkultur, Allgemeinwissen u.v.m.) Sprachen: 🇩🇪 & 🇬🇧 🏆 **Preise** für die ersten 3 Teams sowie den **Lucky Loser** **Gut zu wissen:** Die meisten Fragen sind allgemein verständlich gehalten. Dennoch kann es **hin und wieder Fragen mit Bezug zur deutschen Geschichte, Kultur oder deutschsprachigen Popkultur** geben. Dafür muss man kein Profi sein – **Teamwork ist entscheidend**, und gemischte Teams sind ausdrücklich willkommen. 📸 **Fotos & Promotion:** Während des Quiz machen wir gelegentlich Fotos für **Promo-Zwecke** (Website & Social Media). Falls ihr **nicht** auf Fotos erscheinen möchtet, gebt uns beim Event einfach kurz Bescheid – völlig unkompliziert. Ob alleine, mit Freund:innen oder spontan im Team vor Ort – wir freuen uns auf euch! **Bis bald und viel Spaß beim Quizzen!** 🧠🎉 Wir freuen uns darauf, Sie zu einem Abend zu begrüßen, der Teamgeist, Unterhaltung und jede Menge Spaß verspricht. Wir sehen uns dort!

Let’s celebrate four years of Filmmakers & Movie Nerds with a potluck picnic, karaoke, music, and a proper Movie Nerds party! We’ll start at Tempelhofer Feld with a community potluck. Bring something to share: homemade food, snacks, drinks, or whatever feels easy. Nothing fancy needed. Just something for the improvised table, think hummus, tapas, finger food, sausages, cake, muffins, ... The idea is simple: eat together, meet people, exchange, hang out, and celebrate the community we’ve built. Later, we move to Engels for screenings, karaoke, [Daniel on the decks](https://soundcloud.com/acado_musik/acado-sisyphos), drinks, and beautiful Movie Nerds chaos. **Expect:** 1. Potluck picnic 2. Food and drinks to share 3. Filmmakers hanging out 4. Movie Nerds screening loops 5. Karaoke 6. DJing 7. A full day of community **Schedule:** 15:00: Potluck picnic at Tempelhofer Feld 20:00: Engels opens 22:00: Karaoke 23:00: DJ starts 03:00: Stumbling home with a smile on your face **Locations:** We start at [Tempelhofer Feld](https://maps.app.goo.gl/d8SS2pzGvEhiWybXA), close to the east entrance Later, we move to Engels. If the weather is bad, we go directly to [Café Engels](https://maps.app.goo.gl/mfgNm7XDMt1W84i77). **Who is this for?** Filmmakers, actors, writers, editors, producers, cinematographers, creatives, Movie Nerds, friends, and anyone who wants to be part of an active filmmaking community. You don’t need to know everyone. You don’t need to bring a finished film. Just bring something to share and come celebrate with us. Stop waiting – start celebrating!

**Nerds, Creatives & Dreamers** is a small, curated gathering in Berlin for two kinds of people who almost never end up in the same room: the ones who build things with code, and the ones who build things with imagination. Developers and painters. Engineers and writers. Founders and photographers. In daily life these worlds rarely collide — here, that collision is the whole point. Just a good space, a deliberate mix of curious people, and the freedom to let the evening unfold. Come ready to be surprised by who you meet and where the evening takes you. A room full of curious humans. We’re here to socialize as human beings. And if you do exchange contacts — make it personal, not transactional. **🛠 If You Build Things** · Developers & Engineers · Designers & Product People · Founders · People Who Code for Fun **🎨 If You Create Things** · Writers & Journalists · Photographers · Artists & Painters · Anyone With a Side Obsession 👉 **You can also join via Luma if this event reaches capacity: https://luma.com/0y2yd2q4** Please RSVP “yes” only if you can make it, so we can save a seat for you and others on the waitlist. **📝 Note:** You are welcome to attend our social meetup! The event is free. The space is generously hosted for us — the only thing we ask is that you support it by buying a drink, etc. A small gesture that keeps evenings like this possible. **🤝 Community:** This is a space built on curiosity and respect. We keep it that way — for everyone.

Curious what we do? Check our [Instagram](https://www.instagram.com/filmmakersandmovienerds/) ♥️ Would you like to meet some like-minded filmmakers? Start a project? Or do you need help with a movie you are currently working on? Are you new in the city and you'd like to meet people tinkering with movies? **Then you should join us!** We meet every Sunday. It’s important to us that we get to know each other in person. To create a community of connected people, work, learn and grow together. For film making you need a crew of reliable people with a positive can-do-attitude. This is the place to find them. Together, we will talk about these topics: * What you are currently working on * What you need help with * What would you like to help with * What you you would like to learn This is event is great for: * filmmakers * movie nerds * writers * camera operators * editors * actors * sound recorders * composers * gaffers * producers We are limiting the amount of people, so we can have a structured introduction and discussion. After that we get together loosely with some drinks and chats. And then we mostly go for dinner with a couple of us. **Important information**: *To sustain and grow this amazing community, we started a member contribution that is due every month. The money we collect is used solely for the purpose of the community. Of course you can come once or twice without contributing to check us out!*

The Creative Code Jam is a monthly gathering of artists, makers, designers, illustrators, coders, musicians, performers, learners and anyone interested in the use of computing skills for artistic expression. The event is free and open to all, regardless of age, origin, gender or experience. The jam is an opportunity to meet likeminded people and get creative together in a relaxed and safe environment. Beginners and first-timers should feel especially welcome! WHAT SHOULD I EXPECT? **Bring a laptop** and/or anything you’d like to work on, whether it’s a personal project, an experiment, or a skill you want to learn. You can come with friends or meet new people here. There’s no set agenda: some people code, some sketch ideas, some collaborate, and others just chat and get inspired. SCHEDULE Doors open at noon, then we’ll have quick introductions so everyone can share what they’re planning to work on. Note: arriving on time is the best way to hear what others are up to ;) Around 6 pm, we gather to share what we’ve worked on during the day. BEGINNERS WELCOME! If you’re new to creative coding, we'll be happy to help you get started, and you can find beginner-friendly resources at [creativecode.berlin/learn](http://creativecode.berlin/learn). THIS IS YOUR SPACE We do our best to create a welcoming environment for all people regardless of race, ethnicity, color, religion, gender identity, sexual orientation, national origin, age, disability, or genetics. People from group generally underrepresented in open-source, art, and technology fields are warmly encouraged to come by. And if you know someone who might enjoy this meetup but isn’t sure it’s for them, let them know they’ll be welcome! SAFE SPACE POLICY We support the Berlin Code of Conduct: https://berlincodeofconduct.org/ Please make sure you agree with its content. ABOUT MotionLab.Berlin MotionLab.Berlin is Germany’s premier Innovation Hub & Makerspace – an ecosystem for Hardtech, art, creativity, and entrepreneurship. They are an international community with access to state-of-the-art machinery, prototyping machines, coworking spaces, offices, and production facilities. More info: https://motionlab.berlin/ ACCESSIBILITY MotionLab is located on the ground floor, with bathrooms on that same level, although unfortunately they are too small for wheelchairs. FOOD MotionLab has drinks and snacks for sale. Bio food can be found on LPG at Bouchéstr (\~200m). Their cantine has vegan, vegetarian and other food options until 8pm. DO I NEED TO SPEAK GERMAN? We speak mostly English so international guests are more than welcome! Our team also speaks French, Turkish, Italian, Spanish, Dutch, Finnish and German... though language availability may vary depending on which organizers are present :) CONTACT Raphaël de Courville team@creativecode.berlin +49 176 700 70572 or get in touch via [creativecode.berlin](https://creativecode.berlin/)

➡️ Join us on Telegram: [https://t.me/+1k8nWt2bM7FlZTFi](https://t.me/+1k8nWt2bM7FlZTFi) **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. 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 ☕

**[Reserve a seat on eventbrite](https://ComedyinArtGallery.eventbrite.de)** (<= click here) **Saturday 8pm in an Art Gallery (Mitte)** The perfect blend of art, humour and socialising! **Laughing is contagious 😃 and has the power to bond people🙌** Welcome to an event that deserves your presence. We have booked an Art Gallery in Mitte and are showcasing a creative comedy event that brings people together in a thrilling game format. We will be laughing a lot. **Event Details:** Gallery Opens: 7:30pm Event starts: 8:00pm Event ends: 9:30pm **[Reserve a seat on eventbrite](https://ComedyinArtGallery.eventbrite.de)** (<= click here) **Tickets: Pay what you want (at the end of the show).** This is an English language event. **Host/Comedian:** **Prateek Jajoo (IG: jazz.comedy)** Prateek's been on the top comedy stages from Comedy Cellar in NYC to the cool clubs across Europe. Now, imagine a show that takes you on a hilarious journey through Asia, New York City, and Berlin, all through the eyes of an immigrant trying to integrate in different cultures as a local. IG: @jazz.comedy **Pay what you want (at the end of the show).**

Meet, Match, MoveOn and Manage or Master Why Meet 1)Meet new People Culture Languages. 2)Not Match Romance, Political Views nor Religion, only Respect and Joy 3) Moveon, advance with your level, goals, and especially share and try Rotate the groups and let others participate a bit. 4) Master the challenges, and Manage to give a Like or appreciate the meetups!! **Thematic** or small Concept: Manage to Bring 2 German Friends and you get a Drink. if you bring your Ex Partner + 2 German friends =2 drinks = thats the Challenge and the Attitude of 2026

🎳 **Summer Fun Starts on the Lanes! 20% off for NEW bowlers!** The 6-week summer social bowling league is here - cold drinks, fun times, and new friends await on the lanes! Whether you're looking to meet new people, unwind after work, or just have a fun weekly outing, this league is for everyone. Social vibes, happy hour energy, and plenty of chances to connect with others. No matter your skill level, this league is all about having fun and meeting awesome people. ;) **🗓 Thursday nights \|📍 AMF Sawmill Lanes \| 💵 $74 *(while Early Bird is active)*** **🚨New to the league?** Use discount code (**MUSU26**) for 20% off - $59.20 *during **Early Bird*** **💻 League Info & Registration**: https://bit.ly/ColumbusBowling **Why Join?** 🎉 It’s only 6 weeks - perfect for a low-commitment social plan 🍻 Great mix of people in their 20s, 30s, & 40s, plus post-game hangs at the bar 🎳 Zero pressure - gutter balls totally welcome! 👕 Free league shirt if you sign up early 🧠 Weekly trivia w/ prizes 💬 Super social - join solo or w/ friends! **Want in?** Join our Meetup team Gutter Dusters 👉 **Click here to join** https://tinyurl.com/2d5y52vq Or start a team of your own with a few friends - we’ll all be hanging out either way! 📅 League Dates (Thursday nights): June 25, July 2, July 9, July 16, July 23, July 30 ***(The MeetUp event date is deadline to register for the league.)*** **Cost & What’s Included:** ✔ $74 **Early Bird** registration - **New bowler? Get 20% off w/ code: MUSU26** ✔ 6 weeks of bowling (1–3 games/week) ✔ Shoe rentals & full league setup ✔ Trivia, prizes, and great people 👉 **Sign up now:** 💻League Info & Registration: https://bit.ly/ColumbusBowling 🤑New bowlers use code MUSU26 to save 20% 📸 Follow the fun on Instagram: https://bit.ly/BowlingLeague-IG 📩 Questions? Contact the league: http://bit.ly/2nKHno7 Spots are filling fast – don’t miss out on the fun times!