Kirill Osenkov
@kirillosenkov.com
(Unofficial) VP of Developer Productivity at Microsoft. Developer tools, engineering systems, .NET, C#, Roslyn, Visual Studio, Editor, WPF, Avalonia, MSBuild.
Reposted by Kirill Osenkov
Reposted by Kirill Osenkov
Do you make drag-and-drop interfaces? Or do you wish you did, but they're just too hard?
We're working on a new way to drag & drop! Wanna try it out? Join our study – we'll ask you about your drag-and-drop experiences, and get your hands on the prototype.
Join here: forms.gle/J82tFtu6DqS8.... 🙏!
We're working on a new way to drag & drop! Wanna try it out? Join our study – we'll ask you about your drag-and-drop experiences, and get your hands on the prototype.
Join here: forms.gle/J82tFtu6DqS8.... 🙏!
February 17, 2026 at 11:25 PM
Do you make drag-and-drop interfaces? Or do you wish you did, but they're just too hard?
We're working on a new way to drag & drop! Wanna try it out? Join our study – we'll ask you about your drag-and-drop experiences, and get your hands on the prototype.
Join here: forms.gle/J82tFtu6DqS8.... 🙏!
We're working on a new way to drag & drop! Wanna try it out? Join our study – we'll ask you about your drag-and-drop experiences, and get your hands on the prototype.
Join here: forms.gle/J82tFtu6DqS8.... 🙏!
I encountered a customer experience that's so mindbogglingly bad that I'm just sitting here in disbelief. This is a new record for me.
T-Mobile prepaid refill website basically doesn't work:
prepaid.t-mobile.com/one-time-pay...
T-Mobile prepaid refill website basically doesn't work:
prepaid.t-mobile.com/one-time-pay...
February 17, 2026 at 6:25 AM
I encountered a customer experience that's so mindbogglingly bad that I'm just sitting here in disbelief. This is a new record for me.
T-Mobile prepaid refill website basically doesn't work:
prepaid.t-mobile.com/one-time-pay...
T-Mobile prepaid refill website basically doesn't work:
prepaid.t-mobile.com/one-time-pay...
Reposted by Kirill Osenkov
now that Git 2.53 is out, the Git data model @omarieclaire.bsky.social and I wrote is on the official Git website! git-scm.com/docs/gitdata...
February 14, 2026 at 1:47 PM
now that Git 2.53 is out, the Git data model @omarieclaire.bsky.social and I wrote is on the official Git website! git-scm.com/docs/gitdata...
Reposted by Kirill Osenkov
Treating Maintainer attention as a finite resource: nesbitt.io/2026/02/13/r...
Respectful Open Source
Maintainer attention as a finite resource.
nesbitt.io
February 13, 2026 at 11:32 AM
Treating Maintainer attention as a finite resource: nesbitt.io/2026/02/13/r...
Reposted by Kirill Osenkov
After DIA and DbgHelp, time to dig into ISymUnmanagedReader to get line and source information from .NET Framework symbols - chnasarre.medium.com/7663f9043b6b...
How to support .NET Framework PDB format and source line with ISymUnmanagedReader
After DIA and DbgHelp, time to dig into ISymUnmanagedReader to get its line in source code.
chnasarre.medium.com
February 11, 2026 at 9:18 AM
After DIA and DbgHelp, time to dig into ISymUnmanagedReader to get line and source information from .NET Framework symbols - chnasarre.medium.com/7663f9043b6b...
Reposted by Kirill Osenkov
Heraskevych’s choice to forfeit the medal chance instead of give up the memorial helmet is the biggest story in Ukraine today. Everyone is heartbroken but there is a unanimous consensus that this was what had to happen rather than to give up.
February 12, 2026 at 1:41 PM
Heraskevych’s choice to forfeit the medal chance instead of give up the memorial helmet is the biggest story in Ukraine today. Everyone is heartbroken but there is a unanimous consensus that this was what had to happen rather than to give up.
Reposted by Kirill Osenkov
What It Took to Implement VS Code Debugging for .NET nanoFramework
buff.ly/Vy8azto
#dotnet #IoT #nanoframework #vscode #debugging #csharp
buff.ly/Vy8azto
#dotnet #IoT #nanoframework #vscode #debugging #csharp
What It Took to Implement VS Code Debugging for .NET nanoFramework – .NET nanoFramework
.NET nanoFramework
buff.ly
February 10, 2026 at 7:02 PM
What It Took to Implement VS Code Debugging for .NET nanoFramework
buff.ly/Vy8azto
#dotnet #IoT #nanoframework #vscode #debugging #csharp
buff.ly/Vy8azto
#dotnet #IoT #nanoframework #vscode #debugging #csharp
Corporations. Need. To. Start. Paying.
I for one will think twice before open sourcing anything non-trivial in the future.
I for one will think twice before open sourcing anything non-trivial in the future.
A real risk to almost every org is their extensive use of #oss without compensating the creators. Long-term this is likely to become a real issue.
thenewstack.io/is-open-sour...
thenewstack.io/is-open-sour...
Is Open Source in Trouble?
Open source sustainability requires corporate action, not charity: Igalia engineer proposes concrete pledges to compensate unpaid maintainers
thenewstack.io
February 10, 2026 at 2:13 AM
Corporations. Need. To. Start. Paying.
I for one will think twice before open sourcing anything non-trivial in the future.
I for one will think twice before open sourcing anything non-trivial in the future.
Reposted by Kirill Osenkov
Here is one of the dumbest things about vibe coding that I don't see a lot of people talking about
Imagine you're an open source maintainer and someone opens up a pull request against your repository that they vibe coded. They may or may not tell you they vibe coded it; it doesn't really matter… 🧵
Imagine you're an open source maintainer and someone opens up a pull request against your repository that they vibe coded. They may or may not tell you they vibe coded it; it doesn't really matter… 🧵
February 7, 2026 at 2:05 AM
Here is one of the dumbest things about vibe coding that I don't see a lot of people talking about
Imagine you're an open source maintainer and someone opens up a pull request against your repository that they vibe coded. They may or may not tell you they vibe coded it; it doesn't really matter… 🧵
Imagine you're an open source maintainer and someone opens up a pull request against your repository that they vibe coded. They may or may not tell you they vibe coded it; it doesn't really matter… 🧵
Rewatched Tetris last night (what a great movie!), and fell into a Wikipedia hole reading about Robert Maxwell.
Turns out he died by jumping or falling off his yacht that was named in honor of his daughter, Ghislaine Maxwell.
Turns out he died by jumping or falling off his yacht that was named in honor of his daughter, Ghislaine Maxwell.
February 5, 2026 at 5:06 PM
Rewatched Tetris last night (what a great movie!), and fell into a Wikipedia hole reading about Robert Maxwell.
Turns out he died by jumping or falling off his yacht that was named in honor of his daughter, Ghislaine Maxwell.
Turns out he died by jumping or falling off his yacht that was named in honor of his daughter, Ghislaine Maxwell.
Reposted by Kirill Osenkov
Open Source Maintenance Fee v1.1 robmensching.com/blog/posts/2...
Open Source Maintenance Fee v1.1 | RobMensching.com
Since it's release almost a year ago now, I've been collecting feedback on the Open Source Maintenance Fee. Earlier this week, I integrated a piece of feedback that deserved to bump the version number....
robmensching.com
February 5, 2026 at 8:08 AM
Open Source Maintenance Fee v1.1 robmensching.com/blog/posts/2...
Reposted by Kirill Osenkov
We've released a preview of our completely rewritten Avalonia for VSCode extension.
Powered by the same new XAML parser as our Visual Studio extension, it a ton of new features!
Let us know what you think!
avaloniaui.net/blog/avalon...
Powered by the same new XAML parser as our Visual Studio extension, it a ton of new features!
Let us know what you think!
avaloniaui.net/blog/avalon...
Avalonia for Visual Studio Code - Preview Available - Avalonia UI
The Avalonia for Visual Studio Code Extension Just Got a Whole Lot Smarter
avaloniaui.net
February 4, 2026 at 5:34 PM
We've released a preview of our completely rewritten Avalonia for VSCode extension.
Powered by the same new XAML parser as our Visual Studio extension, it a ton of new features!
Let us know what you think!
avaloniaui.net/blog/avalon...
Powered by the same new XAML parser as our Visual Studio extension, it a ton of new features!
Let us know what you think!
avaloniaui.net/blog/avalon...
Reposted by Kirill Osenkov
have you ever wanted to trap your more annoying collaborators in a code fold? now you can in hazel, thanks to our @automerge.org powered multiplayer mode
February 3, 2026 at 7:17 PM
have you ever wanted to trap your more annoying collaborators in a code fold? now you can in hazel, thanks to our @automerge.org powered multiplayer mode
Reposted by Kirill Osenkov
New video! Memorable for its delightfully absurd name, the Hairy Ball Theorem is extremely beautiful and has some surprising applications: youtu.be/BHdbsHFs2P0
January 31, 2026 at 3:36 PM
New video! Memorable for its delightfully absurd name, the Hairy Ball Theorem is extremely beautiful and has some surprising applications: youtu.be/BHdbsHFs2P0
Reposted by Kirill Osenkov
I have always said it, I will continue to say it, we are limiting the productive potential of millions of freaks by demanding they earn a wage to survive instead of enabling them to do whatever thing their brain is broken for
December 22, 2025 at 12:45 AM
I have always said it, I will continue to say it, we are limiting the productive potential of millions of freaks by demanding they earn a wage to survive instead of enabling them to do whatever thing their brain is broken for
Reposted by Kirill Osenkov
Just blogged, live from @ndcconferences.com #ndclondon, "The Grand Mystery of the Missing 18 Bytes". An exploration of the implementation details affecting different values from benchmark allocation data when compared to memory profiler data in #dotnet.
www.stevejgordon.co.uk/the-grand-my...
www.stevejgordon.co.uk/the-grand-my...
The Grand Mystery of the Missing 18 Bytes - Steve Gordon - Code with Steve
In this post I will share the tale of the mystery surrounding different bytes counts between benchmark data and .NET memory profilers.
www.stevejgordon.co.uk
January 28, 2026 at 3:35 PM
Just blogged, live from @ndcconferences.com #ndclondon, "The Grand Mystery of the Missing 18 Bytes". An exploration of the implementation details affecting different values from benchmark allocation data when compared to memory profiler data in #dotnet.
www.stevejgordon.co.uk/the-grand-my...
www.stevejgordon.co.uk/the-grand-my...
Reposted by Kirill Osenkov
"Its acronym, F.A.F.O., references a slang term for negative consequences." www.nytimes.com/2026/01/27/u...
January 28, 2026 at 1:07 AM
"Its acronym, F.A.F.O., references a slang term for negative consequences." www.nytimes.com/2026/01/27/u...
Reposted by Kirill Osenkov
Big news! 💪 We’re proud to announce a 2-year sponsorship of ControlR — backing open source and building better remote control experiences in RDM. 🚀🤝
devolutions.net/blog/2026/01...
devolutions.net/blog/2026/01...
Devolutions announces a major 2-year sponsorship of ControlR
Devolutions announces a 2-year sponsorship of ControlR, enabling full-time development, long-term sustainability, and native integration into Remote Desktop Manager.
devolutions.net
January 27, 2026 at 4:33 PM
Big news! 💪 We’re proud to announce a 2-year sponsorship of ControlR — backing open source and building better remote control experiences in RDM. 🚀🤝
devolutions.net/blog/2026/01...
devolutions.net/blog/2026/01...
Reposted by Kirill Osenkov
The wait is almost over! I'm excited to be joining Microsoft Fabric as a senior software engineer. I'm grateful for this opportunity to tackle new challenges together with an amazing team, stretching the limits of .NET build technology! I'll also continue as a member of the C# language design team.
January 24, 2026 at 8:52 PM
The wait is almost over! I'm excited to be joining Microsoft Fabric as a senior software engineer. I'm grateful for this opportunity to tackle new challenges together with an amazing team, stretching the limits of .NET build technology! I'll also continue as a member of the C# language design team.
Reposted by Kirill Osenkov
Retired.
Thanks for all the fish!
Thanks for all the fish!
a red and blue background with the words that 's all folks on it
ALT: a red and blue background with the words that 's all folks on it
media.tenor.com
January 21, 2026 at 11:10 AM
Retired.
Thanks for all the fish!
Thanks for all the fish!
Cloned a project. Project doesn't build. Delete global.json. Project builds fine.
It's just a gift that keeps on giving.
It's just a gift that keeps on giving.
January 22, 2026 at 12:02 AM
Cloned a project. Project doesn't build. Delete global.json. Project builds fine.
It's just a gift that keeps on giving.
It's just a gift that keeps on giving.
Reposted by Kirill Osenkov
A 150-year old topology puzzle has been solved thanks to a few very overheated laptops, an origami rhino, and a seemingly unrelated corner of geometry. www.quantamagazine.org/two-twisty-s...
January 21, 2026 at 9:04 PM
A 150-year old topology puzzle has been solved thanks to a few very overheated laptops, an origami rhino, and a seemingly unrelated corner of geometry. www.quantamagazine.org/two-twisty-s...
Reposted by Kirill Osenkov
Any senior .NET devs looking for a new gig? We’ve got openings doing some pretty impactful stuff.
My DMs are open.
My DMs are open.
January 20, 2026 at 4:48 PM
Any senior .NET devs looking for a new gig? We’ve got openings doing some pretty impactful stuff.
My DMs are open.
My DMs are open.
Reposted by Kirill Osenkov
The Ladybug Clock puzzle
January 20, 2026 at 3:20 PM
The Ladybug Clock puzzle