Retro

**Hosted by Sky Czech Republic.** Doors are open from 5:30 pm, talks will start at 6:00 pm. **1\. Marek Svitok \(Sky\) \- Elegance and Safety in Goroutine Management** Concurrent programming is a core strength of Go, but managing multiple goroutines while handling errors and synchronization can quickly become complex and error-prone. The golang.org/x/sync/errgroup package provides a simple and effective abstraction for running multiple goroutines concurrently, propagating the first error encountered, and ensuring all routines complete before proceeding. In this article, we explore why errgroup is a valuable tool, how to use it effectively, and what design patterns emerge from its usage. We also examine how one might implement similar functionality manually, highlighting the pitfalls and edge cases that make a manual approach cumbersome. By comparing manual implementations with the idiomatic errgroup usage, we aim to demonstrate why adopting this package leads to safer, cleaner, and more maintainable concurrent code in Go. **2\. Vilibald Wanca \- Nail the Basics \- S01E03** Go does not use `try/catch` for normal error handling. Instead, it treats errors as explicit return values, while `panic` is reserved for truly exceptional or unrecoverable situations. A panic stops normal execution, runs deferred calls, and can only be intercepted with `recover` inside a deferred function. This makes `panic/recover` closer to an emergency escape hatch than a general exception system. The result is a model that favors clarity and explicit control over hidden flow. By attending the event I agree that photographs and video recordings from this event may be used by Sky Czech Republic for employer branding and promotional purposes across company websites, career pages, social media, third-party profiles, and other communication materials.

**The most welcoming dance floor on a Wednesday night in Prague**💃✨ Forró is a rhythmic Brazilian dance known for its warm, welcoming community and very casual dance floor vibes. ✅ **No experience needed** → We kick off at 7:45 PM with a quick introduction to the basics.🕺 ✅ **No partner needed** → We rotate after every song. If you feel like dancing, simply ask anyone taking a break to join you. 👋 ✅ **No dress code** → Wear casual basics. You can dance in socks or barefoot. 👣 ✅ **No pressure** → There is a bar at the venue for lemonade or some liquid courage. Entry is voluntary (usually 150 CZK via cash or QR code). Social dancing is better than the gym, cheaper than therapy and there is no small talk. If you love to move and want to make new friends, simply show up on Wednesday and let's dance!! 💃✨

We are a group of runners who meet most weeks for a run around the beautiful Vltava River's edge. You can bring your running shoes straight from the office/home office if you don't have time to stop at home. There will be a place to put your bags in the Cafe. We will run about 9 km along the river and have a drink afterwards. Paces vary! We will meet in the square near Kavarna Liberal (Hermanova 6), near the Vltavska metro/tram stop at 6:30 on Wednesday. See you there!

SPEED FRIENDING - COCKTAILS - PRIZES & MORE Let's meet each other! In an effort for community building we are doing The Wednesday Club once a month great venues such as KONTAKT BAR and LE VALMONT, amazing hidden cocktail bars in the heart of Prague, opening their doors exclusively to you for this event. This event is perfect for a night out if you want to meet some new people. You will be able to spend some one-on-one time with each of them, meet friends for life or just to have some interesting encounters. Everyone is welcome as there are no age restrictions for this event. Each round will take 5 minutes and then a bell will ring and it's time to move on to the next person to discover. Not only will you leave with new friends but there are also some opportunities to win prizes. But for that you’ll have to come discover the event for yourself… Tickets: [Mandatory registration here](https://connect.boomevents.org/en/somethingnew-uqvwe/the-wednesday-club-international-speed-friending-asaur) We are very excited to meet you! Somethingnew

**5-a-side Football** practice at Rajská Zahrada artificial grass pitch. No cleats shoes. Maximum of 15 participants for a 3 teams of 5 rotating. **Kick off at 18h00**. Everybody is welcome, no age, gender nor any restriction of any type to join. Cost: **90 crowns**. Please send the money using the **QR Code** stored here: https://imgur.com/a/G8NWGjM In case of any Opt-out within 24h of the session, or no show, the payment will be due (you still can ask someone to come instead of you, as your spot will be booked)

**Join us in Prague for a Snowflake User Group evening hosted by Everpure (formely Pure Storage).** This edition will bring together Snowflake product updates and practical lessons from teams using the platform in production. We’ll begin with a look at recent developments across the Snowflake ecosystem, including selected new features and broader trends shaping the data platform space. The evening will also include a customer session from Everpure's Metrics team, focused on large-scale data pipelines in Snowflake, including Snowpipe Streaming and experience from high-volume production environments. We’ll round things off with an informal fireside chat with a guest from Snowflake, followed by networking, community discussion, and the traditional Snowflake quiz. **EVENT DETAILS** * **What’s New in Snowflake** Kick off the evening with an overview of the latest developments in the Snowflake ecosystem. We’ll cover new features, emerging trends in the data platform space, and a few practical insights from real-world projects. * **Customer Story: Data Pipelines at Scale** Our host company Everpure's Metrics team will share how they use Snowflake in their data pipelines. The session will focus on large-scale ingestion using Snowpipe Streaming, handling around 10 TB of data per day, and lessons learned from operating high-volume pipelines in production. * **Fireside Chat with Snowflake** An informal conversation with a guest directly from Snowflake. We’ll discuss recent platform developments, what’s coming next, and interesting topics shaping the future of data platforms. The chat will be hosted and moderated live. * **The Snowflake Quiz** As always, we’ll close with the Snowflake quiz, a few goodies up for grabs, and time to connect with fellow data professionals over drinks. **RSVP** here [See Snowflake in Action: Prague User Group](https://usergroups.snowflake.com/events/details/snowflake-prague-presents-snowflake-in-action-prague-user-group-hosted-by-pure-storage-1/).

Před několika měsíci vyústila vyostřená debata o filtrech a Core vs Knots v kontroverzní návrh BIP-110, původně známý jako “BIP-444”, neboli Reduce Data Temporary Soft Fork, který má za cíl dočasně omezit časté způsoby vkládání netransakčních dat na bitcoin. Je tento návrh efektivní? Jaké kroky navrhuje? Co se musí stát pro jeho aktivaci a jaká je situace dnes? Lukáš, náš expert na Rust a bitcoin, vám podrobně přiblíží tento problém z každého hlediska. **🦀 PREZENTACE** Tato přednáška představuje BIP-110 v kontextu debaty Knots VS Core, tedy o spam filterech. BIP-110 se snaží se vypořádat se s domnělým i reálným spamem změnou pravidel Bitcoin konsensu, tím že zakáže použití určitých op-kódů a omezí maximální velikosti dat u jiných opcodes. Na BIP-110 se podíváme 1. Z pohledu technického: Co přesně se snaží změnit a proč, kterým metodám se snaží zamezit, a zda zabraňuje některým legitimním použitím bitcoinu 2. Z pohledu časové osy a komunity: Kdy a kým byl BIP-110 vytvořen, kdy se aktivuje a jaké podmínky pro aktivaci musí splnit, jak fungují User-Activated Soft Forky, co se může stát, pokud k jeho aktivaci dojde, a co se může stát, pokud ne 3. Z pohledu efektivity: Jak zapadá do existujících způsobů vkládání netransakčních dat na blockchain, kterým způsobům nezamezuje, a jak se to projeví na ceně vkládání dat **🦀 NETWORKING** Po přibližně 60minutové prezentaci a Q&A zůstáváme na networking u piva. Zůstáváme do 22:00. * Registrace je zdarma. * Bude pití i něco k jídlu. * Odměny za nejlepší otázky. * Knihy od Braiins zdarma. **🦀 PŘEDNÁŠEJÍCÍ** Lukáš Hozda je expert na Rust, autor knihy Building Bitcoin in Rust a lektor kurzů Rust a Advanced Rust na Univerzitě Karlově. Přes den pracuje v pražské bitcoinové softwarové společnosti Braiins, kde jeho oficiální pracovní titul zní Braiins Superman. * Stáhněte si jeho eBook Building Bitcoin in Rust zdarma. * Sledujte Lukáše na X: https://x.com/LukasHozda Pokud vás zajímá seriózní Rust engineering, přidejte se k nám. 🔗 https://braiins.com *** **ENGLISH** 🇺🇸 **Analysis of BIP-110: Timeline, Details and Impacts. Can it work?** A few months ago, a heated debate about filters and Core vs Knots culminated in the controversial proposal BIP-110, originally known as 'BIP-444', or Reduce Data Temporary Soft Fork, which aims to temporarily restrict common methods of inserting non-transactional data onto Bitcoin. Is this proposal effective? What steps does it propose? What needs to happen for it to be activated, and what is the situation today? **🦀 THE PRESENTATION** This lecture presents BIP-110 in the context of the Knots vs Core debate, specifically about spam filters. BIP-110 attempts to deal with both alleged and real spam by changing Bitcoin consensus rules, by banning the use of certain op-codes and restricting the maximum data sizes of other opcodes. We will look at BIP-110 from: 1. A technical perspective: What exactly it tries to change and why, which methods it tries to prevent, and whether it blocks some legitimate uses of Bitcoin 2. A timeline and community perspective: When and by whom BIP-110 was created, when it activates and what conditions it must meet for activation, how User-Activated Soft Forks work, what may happen if it is activated, and what may happen if it is not 3. An effectiveness perspective: How it fits into existing methods of inserting non-transactional data onto the blockchain, which methods it does not prevent, and how this will be reflected in the cost of inserting data **🦀 THE NETWORKING** After about a 60min presentation and Q&A we will stay to network over a beer, we stay until 22:00. * Register here for free entry. * Drinks and snacks provided. * Giveaways for the best Q&A questions. * Braiins Bitcoin books for free. **🦀 THE SPEAKER** Lukáš Hozda is a Rust expert, author of the book Building Bitcoin in Rust, and a lecturer of Rust and Advanced Rust at Charles University. By day, he works at the Prague-based Bitcoin software company Braiins, where his official job title is Braiins Superman. * Download his free eBook [Building Bitcoin in Rust](https://braiins.com/books/building-bitcoin-in-rust) * Follow Lukáš on X: [https://x.com/LukasHozda](https://x.com/LukasHozda) If you are interested in serious Rust engineering, join us. 🔗 [https://braiins.com](https://braiins.com/)

In this session we will discuss the latest novel The Secret of Secrets by American author Dan Brown, a mystery thriller set in Prague. The book was released in September 2025, and follows the adventures of Robert Langdon. We will have a short introduction followed by a simple exercise and sharing of opinions. Before the session, please prepare answers to two tasks: - Please prepare one fact about the book/writing of the book or the author that surprised you. - Please bring one confusing moment from the book that you didn’t understand, or would like to clarify with others.

Capture **modern architecture** with a journey through Prague’s avant-garde edge—where the fluid rhythm of the Vltava meets the daring curves of the new city. Walk, shoot, and connect with photographers & creators as we move from the **Dancing House** into the geometric landscape of **Pankrác**. Beginners, enthusiasts, and pros — all are welcome. –––––––––– **EVENT DETAILS** **Location:** Dancing House (Tančící dům) → Vltava Riverside → Pankrác Plain **Date:** 25.04.2026 **Time:** 17:00 – 19:00 **Meeting Point:** **[I need coffee!](https://maps.app.goo.gl/CTJsJqU81fNf3nBb6)**[ ](https://maps.app.goo.gl/CTJsJqU81fNf3nBb6) **[Adress:](https://maps.app.goo.gl/CTJsJqU81fNf3nBb6)**[ (Na Moráni 1958, 120 00 Nové Město, Czechia)](https://maps.app.goo.gl/CTJsJqU81fNf3nBb6) –––––––––– **EVENT FLOW** **17:00 \| Meet & Connect** We’ll gather at the meeting point, introduce ourselves, and warm up creatively by the riverbank as the afternoon light begins to stretch. **17:30 \| Main Walk \(Architecture & Modern Lines\)** We’ll focus on the deconstructivist curves of the Dancing House before heading toward the sleek skyscrapers of the Pankrác business district. Our lens will capture the interplay of high-gloss glass, bold geometry, and the long, sharp shadows that define Prague’s modern skyline in the late afternoon. **19:00 \| Optional Drinks nearby** We’ll wrap up the official walk near the Arkády area for optional social time and a chance to share our favorite shots. –––––––––– **IMPORTANT** This isn’t a class. It’s not a tour. It’s a creative meetup. We’ll walk. We’ll shoot. We’ll connect. –––––––––– **WHAT TO EXPECT** **Bring your:** * Film camera * Digital camera * Smartphone * Curiosity Whether you're a beginner, seasoned photographer, content creator, or just creatively curious — you’re welcome here. Come solo or bring friends. Spots are limited — reserve your place ASAP. –––––––––– **STAY CONNECTED** 📍 Join our [WhatsApp group](https://chat.whatsapp.com/JOMNmbjUHugCQRFwNVoCcq?mode=gi_t) for live location & updates. 📸 Follow **[@takeaphotowalkcommunity](https://www.instagram.com/takeaphotowalkcommunity)** and tag us in your photos. –––––––––– **ABOUT TAKE A PHOTO WALK** Founded in Barcelona in July 2024, Take a Photo Walk connects photographers and creators around the world through real-life creative experiences. Now **Prague** is part of the story. –––––––––– *Capturing the heartbeat of a city that never stops evolving.* See you in **Prague**. 📸

Hi All, Come and join us for social running and a coffee! We meet at the main gate of Vystaviste - tram stop Vystaviste Holesovice. We will run in Stromovka. Usually we run around 50mins and it is up to everyone how many kilometres. We welcome all levels of runner. We can all run together or, if there is more of us, we can split into groups and at the end of the run we all meet close to the starting point to go for a coffee to a nice local coffee place (where they also sell cakes and great chocolate). If the weather is great, we can also just sit in one of the outside coffee placces in Stromovka and enjoy the sun. This is where we meet: http://photos2.meetupstatic.com/photos/event/7/7/3/1/600_447930513.jpeg

**The Easiest room to walk into on a Saturday night** 🤩🌍 We are a welcoming, high-energy tribe of locals, newcomers, and expats alike. Half the room is our stable core, the other is always brand new! We skip the awkward small talk and go straight for REAL connections ✨, naturally transitioning into a great party 🤩 later on. Our rules are simple: No pressure, no city masks, and absolutely no standing alone. Just grab a drink 🍹 and jump right in. You’ll leave feeling energized, connected, and a little bit more like a true Praguer. 😎🤙 👉 If you want to dive deeper, just show up and JOIN our LOCAL WhatsApp community of 250+ Praguers!

Sing for yourself, Sing for someone, Sing for the moment 🙂Choose your song & let your bathroom artist out :D coz everyone can sing... 👉 Every Friday, we welcome you to join our International Karaoke Nights. Singing or not singing, we guarantee you a lot of fun, making new friends, and meeting international people. 🏅We organise the biggest social events in the Czech Republic where you enjoy amazing cocktails and a variety of drinks, with happy hours waiting for you. 📍LOCATION Tequila Tales Bar & Music Club Újezd 19 118 00 Prague, Czech Republic (Nearest tram stop- Hellichova & Ujezd) ❓Questions❓ Write to https://www.instagram.com/tequilatales_prg/

**6-a-side Football** practice at Pražačka Football artificial grass pitch. Maximum of 36 participants for 6 teams of 6. **Kick off at 12h00**. Everybody is welcome, no age, gender nor any restriction of any type to join. Cost: **90 crowns**. Please send the money using the **QR Code** stored here: https://imgur.com/a/PjU32Fi In case of any Opt-out within 24h of the session, or no show, the payment will be due (you still can ask someone to come instead of you, as your spot will be booked)

Come and join us for a fun, friendly, but competitive game of 7-a-side. All abilities welcome. Artificial, outdoor pitch all year round, whatever the weather. The game starts at 19:30, please be ready to play by then. This football training event is organized by **Taverners FC z.s.** (IČO 23530791). By taking part in this event, each participant confirms that they are responsible for their own health and physical condition. Participation is voluntary and at the participant’s own risk. Taverners FC is not responsible for any injuries, health problems, loss, or damage that may occur during or as a result of participation in the event. Each participant confirms that they are fit to participate. IMPORTANT! A place is ONLY guaranteed for those who are on the list for the event. If you are on the waiting list, please wait patiently until you are on the actual list. Even if you see free spots on the list, but you are still on the waiting list, a place is NOT guaranteed. Also, we do last-minute subs in the Facebook group every Thursday afternoon: https://www.facebook.com/groups/tavernersprague The game costs 60 crowns. Ways to pay: 1\. With cash\. Ideally\, with exact change\, or no more than a 200 crown note\. 2\. On Revolut \- @simonalperovich / QR code at the game\. Late cancellation after 14:00 on the day of the event costs 60 crowns.

**Caller: Richard Ades** **Band: The McKenzies** **Clinton Heights Lutheran Church** **15 Clinton Heights Ave, Columbus, OH 43202** WHAT IS CONTRA DANCING? Picture the Grand Ball scenes like you’ve seen in period films such as “Pride and Prejudice”, where the dancers are lined up in long lines, across from each other. That’s English Country Dancing, the predecessor of contra dancing. Now, add moves like “swing your partner” and “do-si-do,” like you’ve seen in square dancing. Set it to fabulous, high energy, live music with fiddles, guitars, percussion and more, alá “Riverdance.” Finally, set the whole scene down in the middle of Woodstock, with a hip, groovy atmosphere, a bit of tie-dye, and hints of counter-culture attitude. THAT’s Contra Dancing! Wear cool and comfortable clothes (you will get warm) and clean shoes that won't mark up our nice wood floor. Be sure to come for the beginner's lesson from 7:30 - 8:00, followed by dancing 8:00 - 10:30. All dances are taught; we will help you learn! Beginners always welcome, no need to bring a partner. Cost is $10.00 adults, $5.00 ages 12-26. Under 12 free. Free parking in church lot. For more information contact me or check out our website: [www.bigscioty.com](http://www.bigscioty.com/) Please bring your own refillable water bottle.

Mental Health, how do you understand it? How can you improve it? How do you get rid of stress, anxiety and uncertainty? These emotions are buried deep in your reactive mind. Find out what the reactive mind is, and in the process find yourself. Have you ever suffered from a traumatic experience, a deep loss or been through a painful breakup? Has your ability to communicate suffered as a result? And after that, even though you "moved on" did you find that things were never quite the same? Have you ever looked at childhood photos, or reminisced your early life and wondered where that happiness and spark went? Are your emotions out of your own control? Have you ever felt, even if you aren’t aware of it, that possibly you are getting in your own way of your happiness and success? How does this affect your self-confidence? Find out what is at the root of all stress, anxiety, depression and self-doubt. Find out how and why you hold yourself back from achieving your goals and having the life you have dreamed of. As soon as you learn what is at the root of these unwanted conditions, you’ll see it is something you can DO something about. You will not be labeled or categorized at this MeetUp. This group is hosted by the Dianetics and Scientology Life Improvement Center of Central Ohio.

Tickets are now on sale!🥳We also will have lunch before. At the Rusty Bucket in Easton which is posted separately. 😊 Park in the East Garage.The restaurant is across the street then we can walk back together to the movie! 🥳

It’s time to take control of your mental health. How do you get rid of stress, anxiety and uncertainty? These emotions are buried deep in your reactive mind. Find out what the reactive mind is, and in the process find yourself. Have you ever suffered from a traumatic experience, a deep loss or been through a painful breakup? Has your ability to communicate suffered as a result? And after that, even though you "moved on" did you find that things were never quite the same? Have you ever looked at childhood photos, or reminisced your early life and wondered where that happiness and spark went? Are your emotions out of your own control? Have you ever felt, even if you aren’t aware of it, that possibly you are getting in your own way of your happiness and success? How does this affect your self-confidence? Find out what is at the root of all stress, anxiety, depression and self-doubt. Find out how and why you hold yourself back from achieving your goals and having the life you have dreamed of. As soon as you learn what is at the root of these unwanted conditions, you’ll see it is something you can DO something about. You will not be labeled or categorized at this MeetUp.

**Optional movie afterwards**

Feeling down? Sometimes depressed? Can't focus? Negativity & stress? Recent losses? Creativity in career and personal life hindered by mental blocks? Sometimes we never fully recover from traumatic experiences. Whether it was yesterday, last week or a year ago, traumatic experiences - a loss of a loved one, losing a job, a breakup - can leave you scarred. You talk about it and feel a little better, but it never goes away. After you hang up the phone, it's still there; the sadness, the cloud, the over-thinking, the worry, the guilt. You try to focus, but you're blocked. You try to look forward into new experiences, new relationships but a cloud is hanging over you, casting a shadow on what you once considered a bright, cheerful future. What happened to your courage? Your strength of character? You're 'why not' attitude? Whoever said 'time heals' must have had a special time machine, because after weeks, months, years, you're wondering - when exactly does that kick in? Sometimes it seems like drinking or drugs are the way to go. But they wear off, and now the problem is still there with added side effects from the drugs. At this free local Meetup event we will talk about: * What causes grief, anxiety and depression to become chronic. * Is it possible to regain your joy and happiness even after traumatic experiences? * How to break away from negativity and focus on the future * What are the steps to take to get control of your mind and your emotions? Learn about a safe, gentle, do-it-yourself counseling that can be done in the comfort of your own home. Let's explore safe, effective solutions for healing from traumatic experiences. Be sure to click on the red "Attend" button below to come to the event. We look forward to seeing you there. This group is sponsored by the Dianetics & Scientology Life Improvement Center.

Over 50 CINCO de MAYO HAPPY HOUR - FLIGHTS N TACOS!!! Join us for a fun and relaxed Over 50 Happy Hour on Friday, May 1st from 5:00 PM – 8:00 PM at Giant Eagle Grandview Yard Event Center! (upper level) **Plenty of free parking**. The event center is huge! Pics are in the comments. Over 50 CINCO de MAYO HAPPY HOUR!! – Flights n Tacos Let’s join together for a fiesta! (Invite friends - we have lots of room!) • Taco Bar • Margarita and Beer tasting • Complementary chips and salsa • Margs/cocktails at the bar for purchase • Festive Band/Music Margaritas/Mexican Beer Tasting + Taco Bar: Optional - For $15.00 per person you can also get 4 Margarita or beer) Get ready for a fun evening filled with live music, great conversation, and a lively crowd of 50+ singles and friends looking to mix, mingle, and enjoy the night. Whether you come solo or with friends, you’ll quickly feel the welcoming, social vibe. Enjoy happy hour at the bar until 6 PM, or take part in the special Cinco de Mayo experience featuring margarita flights and delicious Mexican bites. It’s the perfect setting to relax, meet new people, and celebrate in style. Our private upstairs space gives us plenty of room to connect, laugh, and enjoy the energy of the night. Come when you can, stay as long as you like — the best conversations (and the most fun!) tend to build as the evening goes on. No agenda — just great people, live music, and a Cinco de Mayo celebration you won’t want to miss!