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
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
Reposted by Kirill Osenkov
New video on Dissecting the Code YouTube channel: ".NET 10 De-Abstraction in Action", that covers how .NET 10 almost completely eliminates the abstraction penalty when iterating over interfaces.
#dotnet10, #performance
#dotnet10, #performance
January 20, 2026 at 4:16 PM
New video on Dissecting the Code YouTube channel: ".NET 10 De-Abstraction in Action", that covers how .NET 10 almost completely eliminates the abstraction penalty when iterating over interfaces.
#dotnet10, #performance
#dotnet10, #performance
Reposted by Kirill Osenkov
You can now subscribe to Avalonia Accelerate on a 'rent-to-own' basis! 🚀
Subscribe for 12 months and receive a perpetual license at the end.
This is just one of the improvements available in our new Avalonia portal. avaloniaui.net/blog/introd...
Subscribe for 12 months and receive a perpetual license at the end.
This is just one of the improvements available in our new Avalonia portal. avaloniaui.net/blog/introd...
January 20, 2026 at 5:39 PM
You can now subscribe to Avalonia Accelerate on a 'rent-to-own' basis! 🚀
Subscribe for 12 months and receive a perpetual license at the end.
This is just one of the improvements available in our new Avalonia portal. avaloniaui.net/blog/introd...
Subscribe for 12 months and receive a perpetual license at the end.
This is just one of the improvements available in our new Avalonia portal. avaloniaui.net/blog/introd...
Reposted by Kirill Osenkov
My latest side project, this takes an MSBuild binlog file and transforms it into a Perfetto trace
msbuild-binlog-perfview.pages.dev
msbuild-binlog-perfview.pages.dev
January 18, 2026 at 10:05 PM
My latest side project, this takes an MSBuild binlog file and transforms it into a Perfetto trace
msbuild-binlog-perfview.pages.dev
msbuild-binlog-perfview.pages.dev
Reposted by Kirill Osenkov
I guess I didn't talk about this much publicly — I, uh, wrote a static site generator last year, to replace hugo and docusaurus for ink & switch.
I think the ratio of "niceness" / LOC is really high.
Also, I think the readme is a good read.
You can take it, hack it, and use it yourself. <3
I think the ratio of "niceness" / LOC is really high.
Also, I think the readme is a good read.
You can take it, hack it, and use it yourself. <3
Everything is in the system folder, and the top level readme covers the basics of how it works and some general philosophy.
NB — this SSG is worse than hugo in almost every way, except for the ones that matter most to us.
Feel free DM if you want lots more design / tech details.
NB — this SSG is worse than hugo in almost every way, except for the ones that matter most to us.
Feel free DM if you want lots more design / tech details.
GitHub - automerge/automerge.github.io: The official website of the Automerge project, with docs, references, community links, and more!
The official website of the Automerge project, with docs, references, community links, and more! - automerge/automerge.github.io
github.com
January 15, 2026 at 9:00 PM
I guess I didn't talk about this much publicly — I, uh, wrote a static site generator last year, to replace hugo and docusaurus for ink & switch.
I think the ratio of "niceness" / LOC is really high.
Also, I think the readme is a good read.
You can take it, hack it, and use it yourself. <3
I think the ratio of "niceness" / LOC is really high.
Also, I think the readme is a good read.
You can take it, hack it, and use it yourself. <3
Reposted by Kirill Osenkov
Thrilled to announce that on wed the 28th, @mrogalski.eu will deliver a workshop on Automat, his exquisite programming system that looks like something out of a dream.
Event details and RSVP: luma.com/gh1yz6jk
Event details and RSVP: luma.com/gh1yz6jk
January 8, 2026 at 12:45 AM
Thrilled to announce that on wed the 28th, @mrogalski.eu will deliver a workshop on Automat, his exquisite programming system that looks like something out of a dream.
Event details and RSVP: luma.com/gh1yz6jk
Event details and RSVP: luma.com/gh1yz6jk
Reposted by Kirill Osenkov
You and your wife drop your 6-year-old off at school. You just moved here. You see ICE terrorizing your new neighbors. You film them, as is your legal right. Your wife complies with orders. She is then shot in the head. You still have to pick up your child later today.
This could be you.
This could be you.
January 8, 2026 at 12:15 AM
You and your wife drop your 6-year-old off at school. You just moved here. You see ICE terrorizing your new neighbors. You film them, as is your legal right. Your wife complies with orders. She is then shot in the head. You still have to pick up your child later today.
This could be you.
This could be you.