C#

Happy 2026! Our first meetup of the year will be back at Zühlke's offices near Old Street, with Guillaume Faas talking about better ways to handle exceptions, Jenny Martin talking about taming complexity with OOPSI, plus the usual drinks, snacks, and plenty of time to chat. Doors 18:30, the first talk starts at 19:00 and we'll be done and heading to the pub at 21:00 to continue the conversation. **Guillaume Faas: Throw exceptions... out of your codebase** Throwing exceptions is often used to handle errors, validations, and other specific use cases. It is considered by many to be the standard way of indicating a failure and providing feedback to the caller. However, this approach can cause significant issues like being hard to detect, obfuscating the flow or leaving the system invalid. In this talk, I want to show you a faster alternative that offers more transparency and predictability. We will see how to integrate ideas from the Functional paradigm, such as "Monads", into an Object-Oriented codebase using a real-life project: Vonage's open-source .NET SDK. This talk will be the perfect opportunity to show you what they are and how easy they are to use. **Guillaume Faas** is a Senior .Net Developer Advocate at Vonage, based in Thionville, France. In recent years, Guillaume has focused on sharing my experience through mentoring, public speaking, and open-source contributions; all aimed at helping teams grow and build sustainable software. With nearly 15 years of experience in .NET development, he's worked across industries as an engineer, coach, and now developer advocate. His current focus is on developer experience: building SDKs, writing approachable technical content, and speaking at conferences around the world. **Jenny Martin: OOPSI: Making Sense of Complexity** OOPSI stands for outcomes, outputs, process, scenarios, inputs. It’s a flexible, easy-to-use collaboration framework that helps agile and product development teams cut through complexity and focus on value. OOPSI is timely because it maximises the intrinsically human aspects of effective delivery, helping teams understand how and when to collaborate, while producing lean, example-driven artefacts that clarify scope and intent so both people and automation can work more effectively. In this talk, you’ll learn how to apply OOPSI to strengthen shared understanding, clarify assumptions, and support testable delivery, using a detailed, end-to-end example. **Jenny Martin** is a practitioner, facilitator, and product discovery specialist with over 25 years’ experience working at the intersection of technology, delivery, and human behaviour. She has spent more than 15 years working with Agile and modern product development teams, helping them make sense of complexity and build shared understanding. Known as The Collaboration Coach, Jenny focuses on practical collaboration that supports effective delivery. She is currently writing a book on OOPSI.

** Tuesday Badminton Session: 8-10 PM at QMSC Victoria** **Queen Mother Sports Centre (Everyone Active), Victoria, SW1** Hi Everyone, **RSVP Required:** Everyone attending the session must RSVP in advance, whether you’re a member, returning player, or joining us for the first time. Members can also confirm attendance by email or text if preferred. ----- ## SESSION FEE: £14 ** Why Pay More? Join as a Member Instead!** **Annual Membership: £450** = just **£8.65/session** (Save £278 per year vs pay-as-you-go!) **3-Month Trial: £155** – test the waters before committing **Student/U25/Unemployed: 20% OFF** all memberships **[View Full Membership Benefits & Join](https://www.sidsbadmintonclub.org.uk/membership.php)** **What You Get as a Member:** ✓ Premium feather shuttles included ✓ Priority access to both venues (Victoria & Richmond) ✓ League team eligibility ✓ Member WhatsApp group & social events ✓ This is a **membership-first club** – join the community! ----- ## SESSION DETAILS **Venue:** Queen Mother Sports Centre (Everyone Active) 223 Vauxhall Bridge Road, Victoria, SW1V 1EL *(5-minute walk from Victoria Station)* **Skill Level:** Lower Intermediate Ladies (C+) | Intermediate Men (B) and above *(No beginners or improvers at Tuesday sessions)* **What’s Included:** • Premium feather shuttles provided (Yonex, Yehlex, Victor) • MatchMaking App grades your skill level based on wins/losses – see how you rank! • 5 courts available for play • Players grouped by skill level • Last 30 mins (when scheduled): grade-based competitive groups on allocated courts ----- ## PAYMENT **Cash preferred** – pay organisers **at the beginning of session** (correct change appreciated) **Bank transfer available** (**NOT for first-timers**) **First-timers:** You must pay at the start of the session and register on our MatchMaking App ----- ## IMPORTANT INFORMATION **Cancellation Policy:** Cancel **24 hours before** or you’ll be charged the full £14 session fee. Outstanding fees **must be cleared** before attending your next session. This helps us run sessions efficiently. **Parking:** Free from 6:30 PM (single yellow lines) and 7:00 PM (single red lines) on Tuesdays. Please check local signage before parking. **Not Sure About Your Level?** Attend your first session – we’ll help assess if it’s the right fit for you! **Liability:** Sid’s Badminton Club is not responsible for personal property loss or injury. ----- **Questions?** Text us on Meetup Email: info@sidsbadmintonclub.org.uk Or use our [Contact Form](https://www.sidsbadmintonclub.org.uk/contact.php) Visit: [www.sidsbadmintonclub.org.uk](https://www.sidsbadmintonclub.org.uk/) **Looking forward to seeing you on court!** *Sid’s Badminton Club – Competitive play since 1981* !​​​​​​​​​

London TypeScript is back! We’re kicking things off with a smaller, more relaxed social before announcing our first major event of 2026. Four Quarters is a great chain of retro arcade bars, with plenty of classic games and a laid-back atmosphere. Come along to play a few games, meet some fellow TypeScript fans, and most importantly, share your ideas and suggestions for the future of London TypeScript.

**BOOK HERE**: https://sportas.co.uk/games/43569 **Game Description:** Mixed nationality and gender players play volleyball in our club for 10 years every Tuesday & Thursday from 8pm-10pm in upper intermediate and advance level. **Rules** Respect each other, focused on your own play and progress, be kind and cheer your team mate.

**BOOK HERE**: https://sportas.co.uk/games/44231 **Game Description:** Come and play in a casual​​​​​​​​​​​​​​​​​​​​​​,​​​​​​​​​​​​​​​​​​​​​​ friendly & social badminton session. The session is for mixed ability players (mainly beginners & intermediate players). So please be respectful and kind towards less experienced players - we all have to start somewhere We use YONEX MAVIS 300 Nylon Shuttlecocks. We have a few spare rackets if needed. Format: We play doubles for the whole time and keep rotating opponents/partners across courts so everyone plays each other. Venue: Entrance to the sports hall is on the corner of Celebration Avenue and Temple Mills Ln There are showers, changing rooms & a water fountain at the venue ‍♂️5 minute walk from Stratford International DLR Station Paid car parking is available on site **Rules** Classic doubles rules - can be explained at the start of the session if you’re new to badminton or need a reminder

**BOOK HERE**: https://sportas.co.uk/games/43984 **Game Description:** Come and join our badminton session in Canning Town Music 3 courts, social session, so no matter your ability you are welcome to join There will be spare rackets but please bring your own racket if you do have one. Plastic shuttles will be provided. Join our whatsapp Group: https://chat.whatsapp.com/LsLjg8CxI8MIxSFb82qkdb Getting Into the School 1\. The school is surrounded by a green fence\. 2\. Entrance is near the stone wall\. 3\. At the gate\, find the intercom on the right\-hand side\. 4\. Press the ‘Call’ button and wait for security to respond\. 5\. When the intercom flashes green\, push the gate open\. \-\-\- Finding the Indoor Court 1\. After entering\, go through the visitor gate\. 2\. Follow the corridor to the end\. 3\. Look for the yellow double doors – the badminton courts are inside\! \-\-\- Facilities Changing Rooms & Toilets \- Located outside the court area in the corridor\. \- Male facilities – right\-hand side\. \- Female facilities – left\-hand side\. Water Points \- There are three water points in the corridor outside the court\. \- Bring a water bottle to use with the water pump\. Enjoy your game! **Rules** Games to 21 points

**Tuesday - Intermediate+ @ George Green's** Come and join our friendly badminton club for a fun and competitive doubles session at George Green’s School in Tower Hamlets! **How it works** * Book your spot here on Meetup – spaces are limited. * Pay by bank transfer before the session – bank details are provided below. * Bring your own racket and non-marking indoor shoes. Feather shuttles are included. **Level** This is an **Intermediate+ session**. You should be able to play clears, smashes, drops, drives, and net shots consistently in games. All players **must be at the right level** for this session. Badminton levels vary between clubs, so we strongly recommend checking out our **Instagram page** to see what *we* class as **Lower Intermediate, Intermediate, and High Intermediate** before booking. We always use the **first game as a level check**. If it becomes clear during that game that the standard isn’t the right match for this session, **you won’t be able to continue beyond that point**. As a **small community club**, we’re unfortunately **unable to offer refunds** in these situations. Please **only book a session if you are happy to accept these conditions**. **Stay connected** We have a club WhatsApp group for updates, photos, and extra playing opportunities. Message Peter on **07561 100 413** after you've played at your first session and we’ll add you! **Venue** * Where: George Green’s School, 100 Manchester Road, E14 3DW (nearest tube: Island Gardens DLR). * On arrival: Let reception know you’re here for the Tower Hamlets Badminton Meetup. **Price** £12 per session, payable in advance. Bank transfer details: **Badminton Go Ltd** Sort code: 60-83-71 Account: 78644858 (Use your name + date as ref)

PLEASE NOTE NEW TIME OF 3Hrs. 19.:00- 22:00PM PLEASE MAKE PAYMENT AT TIME OF BOOKING. PAYMENT BY BANK TRANSFER, DETAILS BELOW. NO CASH PAYMENTS_. Your space is not guaranteed until payment is received. Welcome back....Please note our sessions have now returned to Park View. Thankyou to all those members old and new who continued to come and support and play fantastic games of badminton. We welcome you all back. **Please note moving forward the sessions will be pay before play, regardless of whether you pay online or cash in person** Join us for friendly, competition badminton with like-minded enthusiasts. We have sole use of four courts. Players do not have to attend for the entire duration however the price is the same. Please note we limit the amount of attendees to 24 so that everybody gets a fair number of games. Play is from 19:00pm to 22:00pm The cost is £15 per session, which includes feather shuttles. Please pay via bank transfer to the following account: L Samuels Sort code: 040004 Account number: 99854842 Please include your name and date as reference. If you do not show without notice we reserve the right to charge a full non-attendance fee and persistent offenders may be blocked from our club. So please be thoughtful and let us know in good time if you cannot attend. **Rules of attendance/Disclaimer**. Park View Badminton Club exists purely to offer an opportunity for like-minded players to exercise, play and socialise together and nothing more. All attendees should consider the club as an informal gathering of people who will train together in a loosely structured format. The club is operated and managed by a number of volunteers in their free time and these volunteers cannot accept any responsibility for any events that occur at the club. If you have any medical conditions that could affect you, it’s your responsibility to make the club aware of these. Neither the club nor Park View School will take responsibility for any injury, loss or damage that might arise as a result of participation in club activities. Effective warmup and stretches should be undertaken before play to avoid injury and appropriate clothing and footwear is to be worn whilst playing at all times. Every person attending the club must take full and complete responsibility for their own actions. Know your limits! The club does not discriminate against any attendees of ethnicity, nationality, sexual orientation, religion or beliefs, sex or disability except as a necessary consequence of the requirements of safely training and participating in the required sport. All attendees are expected to behave with mutual respect and in a way that does not endanger others or bring the club into disrepute. Not complying with this may result in suspension or termination of attendance. Any matters of concern should be directed to the administrators via email (parkviewbclub@gmail.com).

Join Queer Greenwich at Ye Olde Rose n Crown for their Thursday Night **Drag Bingo**! Hosted by the legendary hot mess express Miss Aisles (@missaisles). Filled with cheeky stories, hysterical jokes, sing alongs, and plenty of laughs. Come for the fun or the prize of Ten Thousand Laughs (no seriously, there are cash prizes). It is a scream, so dig up those loose coins down the back of your sofa for a bingo ticket or just join in for the socials and giggles! **Where** Ye Olde Rose & Crown Greenwich, SE10 8ER (QG will have tables reserved, so RSVP if you plan to come along. Seating will be first come, first served due to booking limits, but the pub will do its best to accommodate everyone.) **When** Last Thursday of the month: MeetUp from 7:30, and BINGO starts @8pm **How Much** Free to attend and £2.50 per bingo ticket (cash only) to play. Buy as many tickets as you want! There’s usually a “Buy 4, Get 5 Cards” deal as well. See you there.

**BOOK HERE**: https://sportas.co.uk/games/44283 **Game Description:** Come and play in a casual​​​​​​​​​​​​​​​​​​​​​​,​​​​​​​​​​​​​​​​​​​​​​ friendly & social badminton session. The session is for mixed ability players (mainly beginners & intermediate players). So please be respectful and kind towards less experienced players - we all have to start somewhere We use YONEX MAVIS 300 Nylon Shuttlecocks. We have a few spare rackets if needed. Format: We play doubles for the whole time and keep rotating opponents/partners across courts so everyone plays each other. **Venue:** Entrance to the sports hall is on the corner of Celebration Avenue and Temple Mills Ln There are showers, changing rooms & a water fountain at the venue ‍♂️5 minute walk from Stratford International DLR Station Paid car parking is available on site **Rules** Classic doubles rules - can be explained at the start of the session if you’re new to badminton or need a reminder

**BOOK HERE**: https://sportas.co.uk/games/44251 **Game Description:** Come and play in a Lower-intermediate & above volleyball session in Balham ONLY sign up to this session if you’re a LOWER-INTERMEDIATE player or above. If you are a beginner player please don’t sign up to this game, we will cancel and refund you from the game (sorry!). **Directions:** ‍♂️3 minute walk from Balham station (Northern Line). From Balham tube station turn left onto Chestnut Grove road. Walk to the mini roundabout and take a left onto Boundaries Road. After a short walk just past the football pitch​​​​​​​​​​​​​,​​​​​​​​​​​​​ there will be a big green gate on your right. Follow the building around and the sports hall is to your left opposite the hockey pitch. Rules \- 3 teams of 6 \- Games up to 15 points \- Max 2 games in a row \- Please be positive and encouraging to all players

**BOOK HERE**: https://sportas.co.uk/games/40539 **Game Description:** Come and join our social badminton session in Canning Town 2 courts, social session, lower intermediate and above- as long as you can maintain a basic rally, you are more than welcomed to join There will be spare rackets but please bring your own racket if you do have one. Plastic shuttles will be provided. Join our whatsapp Group: https://chat.whatsapp.com/LsLjg8CxI8MIxSFb82qkdb Getting Into the School 1\. The school is surrounded by a green fence\. 2\. Entrance is near the stone wall\. 3\. At the gate\, find the intercom on the right\-hand side\. 4\. Press the ‘Call’ button and wait for security to respond\. 5\. When the intercom flashes green\, push the gate open\. \-\-\- Finding the Indoor Court 1\. After entering\, go through the visitor gate\. 2\. Follow the corridor to the end\. 3\. Look for the yellow double doors – the badminton courts are inside\! \-\-\- Facilities Changing Rooms & Toilets \- Located outside the court area in the corridor\. \- Male facilities – right\-hand side\. \- Female facilities – left\-hand side\. Water Points \- There are three water points in the corridor outside the court\. \- Bring a water bottle to use with the water pump\. Enjoy your game! Rules Games to 21 points

Join us **the night before Elastic{ON} London** for an exclusive meetup, a perfect warm-up to the big day ahead! This is your chance to connect with the Elastic community, mingle with fellow attendees, and get energized for a full day of presentations at Elastic{ON} London. Don’t miss out! Register for the meetup and make sure you’ve also signed up for [Elastic{ON} London](https://www.elastic.co/events/elasticon/london) as well to experience a full day of learning and networking! **Date and Time:** Wednesday, February 25, from 6:00-8:30 PM **Location:** Davidson Building Address: 1st floor, 5 Southampton St, London WC2E 7HA Note: please use Exeter St entrance as the main entrance is closed after 6pm **Agenda:** * 6:00 pm: Doors open; say hi and eat some food * 6:30 pm: #Talk 1 - Re-thinking significant term discovery Mark Harwood - Ex-Elastic Core Developer and Lucene committer * 7:00 pm: Q&A * 7:10 pm: #Talk 2 - From Specs to Play: How I Built a Generative AI Game with Elastic + Microsoft AI Mike Richter - Principal Partner Solution Architect at Microsoft * 7:30 pm: Q&A * 7:40 pm: Networking and event wrap-up * 8:30 pm: Event close If you’re a long-time Elastic user or just starting your journey, this is the perfect opportunity to share ideas, meet new people, and get inspired. Invite your friends and RSVP on this page! **⚡️ Interested in giving a talk? ⚡️** Have you ever considered presenting on your Elastic use case? We welcome 5-10 minute lightning talks, 45-minute deep dives, and everything in between. If you're interested, please submit via our [CFP](https://sessionize.com/elastic-meetups/) or send us an email at [meetups@elastic.co.](http://meetups@elastic.co./)

**BOOK HERE**: https://sportas.co.uk/games/42891 **Game Description:** Come and join our social badminton session in Canning Town Music 3 courts, social session, so no matter your ability you are welcomed to join There will be spare rackets but please bring your own racket if you do have one. Plastic shuttles will be provided. Join our whatsapp Group: https://chat.whatsapp.com/LsLjg8CxI8MIxSFb82qkdb Getting Into the School 1\. The school is surrounded by a green fence\. 2\. Entrance is near the stone wall\. 3\. At the gate\, find the intercom on the right\-hand side\. 4\. Press the ‘Call’ button and wait for security to respond\. 5\. When the intercom flashes green\, push the gate open\. \-\-\- Finding the Indoor Court 1\. After entering\, go through the visitor gate\. 2\. Follow the corridor to the end\. 3\. Look for the yellow double doors – the badminton courts are inside\! \-\-\- Facilities Changing Rooms & Toilets \- Located outside the court area in the corridor\. \- Male facilities – right\-hand side\. \- Female facilities – left\-hand side\. Water Points \- There are three water points in the corridor outside the court\. \- Bring a water bottle to use with the water pump\. Enjoy your game! Rules Games to 21 points

**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** *Spec-Driven Development with GitHub Spec-Kit: From Intent to Implementation* Spec-driven development flips the traditional workflow on its head: instead of code being the source of truth, the specification becomes the backbone of design, collaboration, and delivery. In this session, we’ll explore how GitHub Spec-Kit enables teams to treat specifications as first-class artifacts—living documents that drive architecture, implementation, and verification. You’ll learn how Spec-Kit helps teams clearly express intent using structured, version-controlled specs that live alongside code. We’ll walk through a practical workflow that starts with defining system behavior and constraints, then progressively refines those specs into testable, automatable outcomes. Along the way, we’ll show how specs can reduce ambiguity, improve cross-functional collaboration, and make design decisions explicit before a single line of production code is written. This talk will cover: --What spec-driven development is (and what it isn’t) --How GitHub Spec-Kit fits into modern developer workflows --Using specs to align product, engineering, and AI-assisted development --Real-world examples of turning specs into implementations with confidence Whether you’re building greenfield systems, integrating AI into your stack, or trying to reduce costly rework, spec-driven development offers a scalable way to move faster without sacrificing clarity. Attendees will leave with concrete patterns and a clear mental model for adopting GitHub Spec-Kit in their own projects. **YouTube Link** TBA

On Thursday, March 12, 2026, we will meet at the TEKSystems offices at 700 N Hurstbourne Pkwy. Doors will open at 6:00 p.m., and the presentations will begin sharply at 6:30 p.m. Along with an excellent presentation, TEKsystems will provide food. Please RSVP so we know how much food to order. Afterward, we will go to Brick House Tavern for drinks and food to continue the conversation. The session will also be broadcast at https://twitch.tv/TaleLearnCode. ### Much Ado About Nullable - C# Nullable Reference Types Explained In 2019 (C# 8.0) Microsoft introduced a feature that has generated a lot of confusion, debate and outright dissent. I'm talking about Nullable Reference Types. In this presentation, I we dig into this feature, explore why it exists, what problem it tries to solve, how it works, and how people have critiqued it, so that you as a programmer can decide if and how you want to use it.

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/

We will show a variety of methods for building agents that run in Microsoft Foundry. This covers the different types of agents: Prompt, Multi, and Hosted, as well as the development lifecycle using evals and traces.

Meeting @ Improving's office in Downtown Columbus, near Cosi. Parking is paid, food & drink are free! This time we're hanging out after the long winter break. We are going to look at a group-member's project used to help learn the fundamentals of Go, and if time allows, we can take a look at how we like to build Go projects using AI.

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