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
Hey #dotnet, would you like it if #msbuild (and dotnet build, etc) natively integrated with your CI/CD pipelines for integrated warning/error reporting and such? I've vibe-coded some stuff here that might be interesting to folks: github.com/dotnet/msbui...
November 8, 2025 at 5:20 PM
Hey #dotnet, would you like it if #msbuild (and dotnet build, etc) natively integrated with your CI/CD pipelines for integrated warning/error reporting and such? I've vibe-coded some stuff here that might be interesting to folks: github.com/dotnet/msbui...
Reposted by Kirill Osenkov
We’re teaming up with Google’s Flutter team to bring Impeller to .NET
Impeller is Flutters new GPU-optimised renderer, replacing Skia for better performance on mobile and embedded devices.
This is what open collaboration looks like 🚀
avaloniaui.net/blog/avalon...
Impeller is Flutters new GPU-optimised renderer, replacing Skia for better performance on mobile and embedded devices.
This is what open collaboration looks like 🚀
avaloniaui.net/blog/avalon...
November 7, 2025 at 7:22 AM
We’re teaming up with Google’s Flutter team to bring Impeller to .NET
Impeller is Flutters new GPU-optimised renderer, replacing Skia for better performance on mobile and embedded devices.
This is what open collaboration looks like 🚀
avaloniaui.net/blog/avalon...
Impeller is Flutters new GPU-optimised renderer, replacing Skia for better performance on mobile and embedded devices.
This is what open collaboration looks like 🚀
avaloniaui.net/blog/avalon...
New in MSBuild Structured Log Viewer:
property trail showing reads and writes during evaluation, in order:
github.com/KirillOsenko...
If you've ever had ordering issues where someone reads your property before you wrote to it, this is the tool for you.
property trail showing reads and writes during evaluation, in order:
github.com/KirillOsenko...
If you've ever had ordering issues where someone reads your property before you wrote to it, this is the tool for you.
November 7, 2025 at 3:04 AM
New in MSBuild Structured Log Viewer:
property trail showing reads and writes during evaluation, in order:
github.com/KirillOsenko...
If you've ever had ordering issues where someone reads your property before you wrote to it, this is the tool for you.
property trail showing reads and writes during evaluation, in order:
github.com/KirillOsenko...
If you've ever had ordering issues where someone reads your property before you wrote to it, this is the tool for you.
Reposted by Kirill Osenkov
Interested in working in .NET Tooling? My team is hiring for a few roles. This is a great to impact the .NET ecosystem, work with devs all across Microsoft and help drive the .NET platform forward.
jobs.careers.microsoft.com/global/en/jo...
jobs.careers.microsoft.com/global/en/jo...
jobs.careers.microsoft.com/global/en/jo...
jobs.careers.microsoft.com/global/en/jo...
November 5, 2025 at 1:26 AM
Interested in working in .NET Tooling? My team is hiring for a few roles. This is a great to impact the .NET ecosystem, work with devs all across Microsoft and help drive the .NET platform forward.
jobs.careers.microsoft.com/global/en/jo...
jobs.careers.microsoft.com/global/en/jo...
jobs.careers.microsoft.com/global/en/jo...
jobs.careers.microsoft.com/global/en/jo...
Reposted by Kirill Osenkov
My fellow Washingtonians, 2025 might be an off-cycle election, but we've still got some important measures to weigh in on! Remember to have your ballot in an election drop box by 8:00 pm Tuesday!
More resources, including drop box location and in-person registration & ballot casting, at votewa.gov
More resources, including drop box location and in-person registration & ballot casting, at votewa.gov
Another state that jumps out: Washington.
—Seattle's mayor's race
—also big stakes in Seattle's prosecutor + council + tax measure
—new exec in King County
—control of Spokane
—Olympia's labor measure
—competitive legislative specials
—school boards split on inclusion
—even a statewide referendum
—Seattle's mayor's race
—also big stakes in Seattle's prosecutor + council + tax measure
—new exec in King County
—control of Spokane
—Olympia's labor measure
—competitive legislative specials
—school boards split on inclusion
—even a statewide referendum
November 4, 2025 at 4:17 AM
My fellow Washingtonians, 2025 might be an off-cycle election, but we've still got some important measures to weigh in on! Remember to have your ballot in an election drop box by 8:00 pm Tuesday!
More resources, including drop box location and in-person registration & ballot casting, at votewa.gov
More resources, including drop box location and in-person registration & ballot casting, at votewa.gov
In Odesa, a man's watch broke. He sees a store with the clock sign, walks in, says my watch is broken.
The store owner: but we don't repair watches.
Man: what do you do?
Store owner: circumcision
Man: but why is there a clock sign?
Store owner: what would you like me to hang up there instead?
The store owner: but we don't repair watches.
Man: what do you do?
Store owner: circumcision
Man: but why is there a clock sign?
Store owner: what would you like me to hang up there instead?
November 3, 2025 at 6:41 PM
In Odesa, a man's watch broke. He sees a store with the clock sign, walks in, says my watch is broken.
The store owner: but we don't repair watches.
Man: what do you do?
Store owner: circumcision
Man: but why is there a clock sign?
Store owner: what would you like me to hang up there instead?
The store owner: but we don't repair watches.
Man: what do you do?
Store owner: circumcision
Man: but why is there a clock sign?
Store owner: what would you like me to hang up there instead?
Reposted by Kirill Osenkov
“In my work with the (Nuremberg Trial) defendants, I was searching for the nature of evil, and I now think I have come close to defining it. A lack of empathy... a genuine incapacity to feel with their fellow men. Evil, I think, is the absence of empathy.”
- Captain G.M. Gilbert, US Army
- Captain G.M. Gilbert, US Army
October 29, 2025 at 9:37 PM
“In my work with the (Nuremberg Trial) defendants, I was searching for the nature of evil, and I now think I have come close to defining it. A lack of empathy... a genuine incapacity to feel with their fellow men. Evil, I think, is the absence of empathy.”
- Captain G.M. Gilbert, US Army
- Captain G.M. Gilbert, US Army
Reposted by Kirill Osenkov
Folks,
The Windows Server Storage team is looking for you input about the ReFS filesystem. We would greatly appreciated if you respond to the survey below. Thanks!
forms.microsoft.com/pages/respon...
The Windows Server Storage team is looking for you input about the ReFS filesystem. We would greatly appreciated if you respond to the survey below. Thanks!
forms.microsoft.com/pages/respon...
Microsoft Forms
forms.microsoft.com
October 29, 2025 at 8:12 PM
Folks,
The Windows Server Storage team is looking for you input about the ReFS filesystem. We would greatly appreciated if you respond to the survey below. Thanks!
forms.microsoft.com/pages/respon...
The Windows Server Storage team is looking for you input about the ReFS filesystem. We would greatly appreciated if you respond to the survey below. Thanks!
forms.microsoft.com/pages/respon...
Reposted by Kirill Osenkov
I'm writing another book, and the first few chapters are available through Manning Early Access now! For 50% off!
hubs.la/Q03Q9PGP0
More details, and the story of how I came to write it, are on my blog at
ericlippert.com/2025/10/30/i...
It feels great to be writing again after a long break. :)
hubs.la/Q03Q9PGP0
More details, and the story of how I came to write it, are on my blog at
ericlippert.com/2025/10/30/i...
It feels great to be writing again after a long break. :)
Fabulous Adventures in Data Structures and Algorithms - Eric Lippert
Author Eric Lippert introduces fabulous solutions using uncommon algorithms and data structures.
There’s a lot more to algorithms than the useful-but-boring recipes you recite for every interview. Th...
hubs.la
October 30, 2025 at 4:39 PM
I'm writing another book, and the first few chapters are available through Manning Early Access now! For 50% off!
hubs.la/Q03Q9PGP0
More details, and the story of how I came to write it, are on my blog at
ericlippert.com/2025/10/30/i...
It feels great to be writing again after a long break. :)
hubs.la/Q03Q9PGP0
More details, and the story of how I came to write it, are on my blog at
ericlippert.com/2025/10/30/i...
It feels great to be writing again after a long break. :)
Reposted by Kirill Osenkov
Oh look, a new book by @ericlippert.com! Should be a fabulous adventure indeed. www.manning.com/books/fabulo...
Fabulous Adventures in Data Structures and Algorithms - Eric Lippert
Author Eric Lippert introduces fabulous solutions using uncommon algorithms and data structures.
There’s a lot more to algorithms than the useful-but-boring recipes you recite for every interview. Th...
www.manning.com
October 30, 2025 at 3:21 PM
Oh look, a new book by @ericlippert.com! Should be a fabulous adventure indeed. www.manning.com/books/fabulo...
Reposted by Kirill Osenkov
With my small company I sponsor open source packages 📦 💶 for a small amount per month. It’s almost unbelievable but last time I checked I was one of the very few sponsors for FluentValidation. OSS needs more companies chipping in!
🎉 Sponsorships are now live on NuGet.org!
🤝 Easily support your favorite package authors
💰 Maintainers: it’s easy to get visibility for funding needs
🌱 NuGet Community grows stronger together
Read the blog post: aka.ms/nuget/sponso...
#NuGet #dotnet #OpenSource
🤝 Easily support your favorite package authors
💰 Maintainers: it’s easy to get visibility for funding needs
🌱 NuGet Community grows stronger together
Read the blog post: aka.ms/nuget/sponso...
#NuGet #dotnet #OpenSource
Announcing Sponsorship on NuGet.org - .NET Blog
Announcing Sponsorship on NuGet.org - An easy way to recognize package maintainers and grow the NuGet community stronger!
aka.ms
October 24, 2025 at 8:21 AM
With my small company I sponsor open source packages 📦 💶 for a small amount per month. It’s almost unbelievable but last time I checked I was one of the very few sponsors for FluentValidation. OSS needs more companies chipping in!
Reposted by Kirill Osenkov
🎉 Sponsorships are now live on NuGet.org!
🤝 Easily support your favorite package authors
💰 Maintainers: it’s easy to get visibility for funding needs
🌱 NuGet Community grows stronger together
Read the blog post: aka.ms/nuget/sponso...
#NuGet #dotnet #OpenSource
🤝 Easily support your favorite package authors
💰 Maintainers: it’s easy to get visibility for funding needs
🌱 NuGet Community grows stronger together
Read the blog post: aka.ms/nuget/sponso...
#NuGet #dotnet #OpenSource
Announcing Sponsorship on NuGet.org - .NET Blog
Announcing Sponsorship on NuGet.org - An easy way to recognize package maintainers and grow the NuGet community stronger!
aka.ms
October 23, 2025 at 10:38 PM
🎉 Sponsorships are now live on NuGet.org!
🤝 Easily support your favorite package authors
💰 Maintainers: it’s easy to get visibility for funding needs
🌱 NuGet Community grows stronger together
Read the blog post: aka.ms/nuget/sponso...
#NuGet #dotnet #OpenSource
🤝 Easily support your favorite package authors
💰 Maintainers: it’s easy to get visibility for funding needs
🌱 NuGet Community grows stronger together
Read the blog post: aka.ms/nuget/sponso...
#NuGet #dotnet #OpenSource
Reposted by Kirill Osenkov
A retrospective of my tech career - a work-focused autobiography, basically - feels a bit vain, but I'm hopeful that it is interesting or useful enough to justify that.
If nothing else writing it up forced me to try to remember what actually happened.
randomascii.wordpress.com/2025/10/22/r...
If nothing else writing it up forced me to try to remember what actually happened.
randomascii.wordpress.com/2025/10/22/r...
Reflections on My Tech Career – Part 1
I’ve been lucky enough to have had a successful career as a software developer. Spanning six companies and thirty-seven years I’ve had the opportunity to work on Elastic Reality, Xbox, Windows, Ste…
randomascii.wordpress.com
October 22, 2025 at 9:05 PM
A retrospective of my tech career - a work-focused autobiography, basically - feels a bit vain, but I'm hopeful that it is interesting or useful enough to justify that.
If nothing else writing it up forced me to try to remember what actually happened.
randomascii.wordpress.com/2025/10/22/r...
If nothing else writing it up forced me to try to remember what actually happened.
randomascii.wordpress.com/2025/10/22/r...
Reposted by Kirill Osenkov
ICYMI: Cake now supports file-based apps using "dotnet run" in .NET 10. Big shoutout to @devlead.se for all his hard work! 👏
October 21, 2025 at 11:48 PM
ICYMI: Cake now supports file-based apps using "dotnet run" in .NET 10. Big shoutout to @devlead.se for all his hard work! 👏
Reposted by Kirill Osenkov
Okay, for the folks who asked: here's the majority AI view, writing up the reasonable, thoughtful view on AI that the vast majority of people in tech hold, that gets overshadowed by the bluster and hype of the tycoons trying to shill their nonsense. anildash.com/2025/10/17/t... Please share!
The Majority AI View - Anil Dash
A blog about making culture. Since 1999.
anildash.com
October 17, 2025 at 7:29 PM
Okay, for the folks who asked: here's the majority AI view, writing up the reasonable, thoughtful view on AI that the vast majority of people in tech hold, that gets overshadowed by the bluster and hype of the tycoons trying to shill their nonsense. anildash.com/2025/10/17/t... Please share!
Reposted by Kirill Osenkov
#SPLASH folks, check out our OOPSLA talk today at 10:30 on Syntactic Completions with Material Obligations! @dm0ney.bsky.social will discuss how we turn arbitrary text into parsed trees by error correction with a generalization of holes called obligations, turning parsing into structure editing!
October 17, 2025 at 12:12 AM
#SPLASH folks, check out our OOPSLA talk today at 10:30 on Syntactic Completions with Material Obligations! @dm0ney.bsky.social will discuss how we turn arbitrary text into parsed trees by error correction with a generalization of holes called obligations, turning parsing into structure editing!
Reposted by Kirill Osenkov
PowerShell Universal joins Devolutions — a big step for IT automation.
Flexible orchestration today, deeper integrations with RDM (Avalonia) and Devolutions Gateway for secure just-in-time automation tomorrow.
Read the blog & share your ideas: devo-inc.net/4oifZIb
#PowerSh#PowerShellt#Automationhref="/hashtag/RDM" class="hover:underline text-blue-600 dark:text-sky-400 no-card-link">#RDM
Flexible orchestration today, deeper integrations with RDM (Avalonia) and Devolutions Gateway for secure just-in-time automation tomorrow.
Read the blog & share your ideas: devo-inc.net/4oifZIb
#PowerSh#PowerShellt#Automationhref="/hashtag/RDM" class="hover:underline text-blue-600 dark:text-sky-400 no-card-link">#RDM
October 16, 2025 at 3:00 PM
PowerShell Universal joins Devolutions — a big step for IT automation.
Flexible orchestration today, deeper integrations with RDM (Avalonia) and Devolutions Gateway for secure just-in-time automation tomorrow.
Read the blog & share your ideas: devo-inc.net/4oifZIb
#PowerSh#PowerShellt#Automationhref="/hashtag/RDM" class="hover:underline text-blue-600 dark:text-sky-400 no-card-link">#RDM
Flexible orchestration today, deeper integrations with RDM (Avalonia) and Devolutions Gateway for secure just-in-time automation tomorrow.
Read the blog & share your ideas: devo-inc.net/4oifZIb
#PowerSh#PowerShellt#Automationhref="/hashtag/RDM" class="hover:underline text-blue-600 dark:text-sky-400 no-card-link">#RDM
Reposted by Kirill Osenkov
PowerShell Universal joins Devolutions ✨
Together with @adamrdriscoll.com, we're building momentum for innovation and creating new exciting integration opportunities 💡
Read more in my latest blog post 👇
blog.devolutions.net/2025/10/powe...
Together with @adamrdriscoll.com, we're building momentum for innovation and creating new exciting integration opportunities 💡
Read more in my latest blog post 👇
blog.devolutions.net/2025/10/powe...
PowerShell Universal joins Devolutions: a new chapter in IT automation
PowerShell Universal joins Devolutions, marking a new chapter in automation, innovation, and collaboration with creator Adam Driscoll.
blog.devolutions.net
October 16, 2025 at 3:18 PM
PowerShell Universal joins Devolutions ✨
Together with @adamrdriscoll.com, we're building momentum for innovation and creating new exciting integration opportunities 💡
Read more in my latest blog post 👇
blog.devolutions.net/2025/10/powe...
Together with @adamrdriscoll.com, we're building momentum for innovation and creating new exciting integration opportunities 💡
Read more in my latest blog post 👇
blog.devolutions.net/2025/10/powe...
Reposted by Kirill Osenkov
C# 14 in the preview introduces partial constructors and events.
They must include exactly one defining declaration and one implementing declaration.
The implementation declaration of a partial event must include add and remove accessors.
They must include exactly one defining declaration and one implementing declaration.
The implementation declaration of a partial event must include add and remove accessors.
October 15, 2025 at 6:37 PM
C# 14 in the preview introduces partial constructors and events.
They must include exactly one defining declaration and one implementing declaration.
The implementation declaration of a partial event must include add and remove accessors.
They must include exactly one defining declaration and one implementing declaration.
The implementation declaration of a partial event must include add and remove accessors.
Reposted by Kirill Osenkov
C# 14 in the preview allows the null conditional member access operator on the left-hand side of an assignment.
Previously, you had to check if the customer was null before assigning the order.
In C# 14, the GetCurrentOrder method is not called if the customer is null.
Previously, you had to check if the customer was null before assigning the order.
In C# 14, the GetCurrentOrder method is not called if the customer is null.
October 13, 2025 at 5:39 PM
C# 14 in the preview allows the null conditional member access operator on the left-hand side of an assignment.
Previously, you had to check if the customer was null before assigning the order.
In C# 14, the GetCurrentOrder method is not called if the customer is null.
Previously, you had to check if the customer was null before assigning the order.
In C# 14, the GetCurrentOrder method is not called if the customer is null.
Solving the astronomy quiz here was delightful, and not hard. Don't read the tweet text (it contains a mild spoiler), just the picture alone is enough to deduce the answer:
was it taken before sunrise or after sunset?
was it taken before sunrise or after sunset?
Comet C/2025 A6 (Lemmon) beautifully captured by astro-photographer Petr Horálek on October 9, from the shore of Seč Lake, Czech Republic.
Check out his other works at www.petrhoralek.com
Quiz: Was this photo taken before sunrise or after sunset?
#Astronomy
1/n
Check out his other works at www.petrhoralek.com
Quiz: Was this photo taken before sunrise or after sunset?
#Astronomy
1/n
October 12, 2025 at 7:23 PM
Solving the astronomy quiz here was delightful, and not hard. Don't read the tweet text (it contains a mild spoiler), just the picture alone is enough to deduce the answer:
was it taken before sunrise or after sunset?
was it taken before sunrise or after sunset?
Reposted by Kirill Osenkov
C# 14 in the preview introduces extension members
There is a new extension keyword that lets you define extension blocks for extension properties, methods, and operators
This means you can group related extension members, enhancing code readability and maintainability
Do you like the new feature?
There is a new extension keyword that lets you define extension blocks for extension properties, methods, and operators
This means you can group related extension members, enhancing code readability and maintainability
Do you like the new feature?
October 12, 2025 at 6:22 PM
C# 14 in the preview introduces extension members
There is a new extension keyword that lets you define extension blocks for extension properties, methods, and operators
This means you can group related extension members, enhancing code readability and maintainability
Do you like the new feature?
There is a new extension keyword that lets you define extension blocks for extension properties, methods, and operators
This means you can group related extension members, enhancing code readability and maintainability
Do you like the new feature?
Reposted by Kirill Osenkov
I couldn’t find a decent syntax highlighting library for .NET — so I built one while working on my AI coding assistant CodePunk.
Say hello to CodePunk.Highlight
🔗 github.com/neil-gilbert...
Say hello to CodePunk.Highlight
🔗 github.com/neil-gilbert...
October 11, 2025 at 1:34 PM
I couldn’t find a decent syntax highlighting library for .NET — so I built one while working on my AI coding assistant CodePunk.
Say hello to CodePunk.Highlight
🔗 github.com/neil-gilbert...
Say hello to CodePunk.Highlight
🔗 github.com/neil-gilbert...
Reposted by Kirill Osenkov
VelloSharp v0.5.0-alpha.1 is now available, delivering Vello’s high-performance 2D GPU engine to .NET atop the wgpu 3D backend. Integrates cleanly with Avalonia, WPF, and WinForms to modernize rendering pipelines without disruptive rewrites. Details: github.com/wieslawsolte...
Release VelloSharp v0.5.0-alpha.1 · wieslawsoltes/VelloSharp
github.com
October 11, 2025 at 9:49 PM
VelloSharp v0.5.0-alpha.1 is now available, delivering Vello’s high-performance 2D GPU engine to .NET atop the wgpu 3D backend. Integrates cleanly with Avalonia, WPF, and WinForms to modernize rendering pipelines without disruptive rewrites. Details: github.com/wieslawsolte...
