Fons Sonnemans
@fonssonnemans.bsky.social
Trainer, speaker, developer, mentor | Microsoft MVP | C#, XAML (UWP, WPF, WinUI3), ASP.NET, Blazor, SQL | husband & father | ballroom dancing | badminton
Pinned
Just launched my new game Number Match – Pairs & Sum of 10 on the Microsoft Store!
A relaxing but brain‑boosting puzzle you can play anytime. Addictive, clean, and surprisingly challenging.
Free download 👇
apps.microsoft.com/detail/9NPGC...
#gamedev #MicrosoftStore #Windows
A relaxing but brain‑boosting puzzle you can play anytime. Addictive, clean, and surprisingly challenging.
Free download 👇
apps.microsoft.com/detail/9NPGC...
#gamedev #MicrosoftStore #Windows
Reposted by Fons Sonnemans
Can you go to bed with specs and wake up to a Windows app?
The Ralph Loop is the dream of AI software. Write the specs, go to bed, and wake up with a working app. So how does it work with Windows app development?
The Ralph Loop is the dream of AI software. Write the specs, go to bed, and wake up with a working app. So how does it work with Windows app development?
Can you go to bed with specs and wake up to a Windows app?
The Ralph Loop is the dream of AI software. Write the specs, go to bed, and wake up with a working app. So how does it work with Windows app development?
joefinapps.com
February 10, 2026 at 5:42 AM
Can you go to bed with specs and wake up to a Windows app?
The Ralph Loop is the dream of AI software. Write the specs, go to bed, and wake up with a working app. So how does it work with Windows app development?
The Ralph Loop is the dream of AI software. Write the specs, go to bed, and wake up with a working app. So how does it work with Windows app development?
Reposted by Fons Sonnemans
My 2D Mahjong game has 41 ratings in the US and a 4.9 score, yet it hasn’t moved up in the Microsoft Store rankings for weeks. Meanwhile, games with zero ratings sit above it — and many others haven’t been reviewed in years.
This ranking system makes no sense.
#MicrosoftStore #indiegames
This ranking system makes no sense.
#MicrosoftStore #indiegames
February 9, 2026 at 11:04 AM
My 2D Mahjong game has 41 ratings in the US and a 4.9 score, yet it hasn’t moved up in the Microsoft Store rankings for weeks. Meanwhile, games with zero ratings sit above it — and many others haven’t been reviewed in years.
This ranking system makes no sense.
#MicrosoftStore #indiegames
This ranking system makes no sense.
#MicrosoftStore #indiegames
Reposted by Fons Sonnemans
People give a lot of advice to junior developers.
Do you know the worst advice I got back when I was still a junior?
It's not what you think:
Do you know the worst advice I got back when I was still a junior?
It's not what you think:
February 9, 2026 at 12:01 PM
People give a lot of advice to junior developers.
Do you know the worst advice I got back when I was still a junior?
It's not what you think:
Do you know the worst advice I got back when I was still a junior?
It's not what you think:
My 2D Mahjong game has 41 ratings in the US and a 4.9 score, yet it hasn’t moved up in the Microsoft Store rankings for weeks. Meanwhile, games with zero ratings sit above it — and many others haven’t been reviewed in years.
This ranking system makes no sense.
#MicrosoftStore #indiegames
This ranking system makes no sense.
#MicrosoftStore #indiegames
February 9, 2026 at 11:04 AM
My 2D Mahjong game has 41 ratings in the US and a 4.9 score, yet it hasn’t moved up in the Microsoft Store rankings for weeks. Meanwhile, games with zero ratings sit above it — and many others haven’t been reviewed in years.
This ranking system makes no sense.
#MicrosoftStore #indiegames
This ranking system makes no sense.
#MicrosoftStore #indiegames
Reposted by Fons Sonnemans
Podman
Podman as a drop in replacement for Docker Desktop
wilbertvandolleweerd.com
February 7, 2026 at 4:17 PM
Reposted by Fons Sonnemans
Another video on Dissecting the Code YouTube channel: "ConfigureAwait best practices".
I feel we have a cargo cult on using ConfigureAwait without thinking too much.
youtu.be/bUHQeY-DlBc?...
I feel we have a cargo cult on using ConfigureAwait without thinking too much.
youtu.be/bUHQeY-DlBc?...
Stop using ConfigureAwait(false) incorrectly!
YouTube video by Dissecting The Code
youtu.be
February 4, 2026 at 4:46 PM
Another video on Dissecting the Code YouTube channel: "ConfigureAwait best practices".
I feel we have a cargo cult on using ConfigureAwait without thinking too much.
youtu.be/bUHQeY-DlBc?...
I feel we have a cargo cult on using ConfigureAwait without thinking too much.
youtu.be/bUHQeY-DlBc?...
Reposted by Fons Sonnemans
High‑performance terrain in .NET isn’t magic — it’s data‑oriented design, SIMD, and clever parallelism.
This #dotNETConf session shows how to build terrain systems that stay fast even when the world gets huge.
▶️ Watch: buff.ly/TXGoBSN
This #dotNETConf session shows how to build terrain systems that stay fast even when the world gets huge.
▶️ Watch: buff.ly/TXGoBSN
February 3, 2026 at 12:45 AM
High‑performance terrain in .NET isn’t magic — it’s data‑oriented design, SIMD, and clever parallelism.
This #dotNETConf session shows how to build terrain systems that stay fast even when the world gets huge.
▶️ Watch: buff.ly/TXGoBSN
This #dotNETConf session shows how to build terrain systems that stay fast even when the world gets huge.
▶️ Watch: buff.ly/TXGoBSN
Reposted by Fons Sonnemans
Blogged: Creating and consuming metrics with System.Diagnostics.Metrics APIs
andrewlock.net/creating-and...
In this post I provide an introduction to the System.Diagnostics.Metrics API, show how to create a custom metric, and show how to read it with dotnet-counters
#dotnet
andrewlock.net/creating-and...
In this post I provide an introduction to the System.Diagnostics.Metrics API, show how to create a custom metric, and show how to read it with dotnet-counters
#dotnet
Creating and consuming metrics with System.Diagnostics.Metrics APIs
In this post I provide an introduction to the System.Diagnostics.Metrics API, and show how to create a custom metric and read it with dotnet-coutners
andrewlock.net
January 27, 2026 at 3:26 PM
Blogged: Creating and consuming metrics with System.Diagnostics.Metrics APIs
andrewlock.net/creating-and...
In this post I provide an introduction to the System.Diagnostics.Metrics API, show how to create a custom metric, and show how to read it with dotnet-counters
#dotnet
andrewlock.net/creating-and...
In this post I provide an introduction to the System.Diagnostics.Metrics API, show how to create a custom metric, and show how to read it with dotnet-counters
#dotnet
Reposted by Fons Sonnemans
After a long wait, I've finally published the sixth part in my "Writing a .NET Garbage Collector in C#" series. Today, we start implementing mark and sweep.
minidump.net/writing-a-ne...
minidump.net/writing-a-ne...
Writing a .NET Garbage Collector in C# - Part 6: Mark and Sweep
Using NativeAOT to write a .NET GC in C#. In the sixth part, we start implementing the mark phase of the garbage collection.
minidump.net
January 27, 2026 at 10:26 AM
After a long wait, I've finally published the sixth part in my "Writing a .NET Garbage Collector in C#" series. Today, we start implementing mark and sweep.
minidump.net/writing-a-ne...
minidump.net/writing-a-ne...
Reposted by Fons Sonnemans
WinDev Helper - A WinUI Extension for VS Code
buff.ly/TSMlojg
Still working out the kinks - Submit issues and feature requests here: buff.ly/FDzXpv9
#windowsdev #winui #windowsappsdk #vscode #dotnet
buff.ly/TSMlojg
Still working out the kinks - Submit issues and feature requests here: buff.ly/FDzXpv9
#windowsdev #winui #windowsappsdk #vscode #dotnet
WinDev Helper - Visual Studio Marketplace
Extension for Visual Studio Code - Build beautiful, performant WinUI apps with VS Code. Debug, build, package, and deploy Windows apps powered by the Windows App SDK.
buff.ly
January 26, 2026 at 3:01 PM
WinDev Helper - A WinUI Extension for VS Code
buff.ly/TSMlojg
Still working out the kinks - Submit issues and feature requests here: buff.ly/FDzXpv9
#windowsdev #winui #windowsappsdk #vscode #dotnet
buff.ly/TSMlojg
Still working out the kinks - Submit issues and feature requests here: buff.ly/FDzXpv9
#windowsdev #winui #windowsappsdk #vscode #dotnet
Reposted by Fons Sonnemans
Just launched my new game Number Match – Pairs & Sum of 10 on the Microsoft Store!
A relaxing but brain‑boosting puzzle you can play anytime. Addictive, clean, and surprisingly challenging.
Free download 👇
apps.microsoft.com/detail/9NPGC...
#gamedev #MicrosoftStore #Windows
A relaxing but brain‑boosting puzzle you can play anytime. Addictive, clean, and surprisingly challenging.
Free download 👇
apps.microsoft.com/detail/9NPGC...
#gamedev #MicrosoftStore #Windows
January 20, 2026 at 10:49 AM
Just launched my new game Number Match – Pairs & Sum of 10 on the Microsoft Store!
A relaxing but brain‑boosting puzzle you can play anytime. Addictive, clean, and surprisingly challenging.
Free download 👇
apps.microsoft.com/detail/9NPGC...
#gamedev #MicrosoftStore #Windows
A relaxing but brain‑boosting puzzle you can play anytime. Addictive, clean, and surprisingly challenging.
Free download 👇
apps.microsoft.com/detail/9NPGC...
#gamedev #MicrosoftStore #Windows
Reposted by Fons Sonnemans
My Surface tablet is acting weird: many apps don’t show the Min/Max/Close buttons. Some apps (Office, Edge, Notepad, Photos, Snipping Tool) are fine, but others like Settings, Store, Calculator, and Clock have none. Anyone know what might be causing this?
#Windows11
#Windows11
January 12, 2026 at 4:34 PM
My Surface tablet is acting weird: many apps don’t show the Min/Max/Close buttons. Some apps (Office, Edge, Notepad, Photos, Snipping Tool) are fine, but others like Settings, Store, Calculator, and Clock have none. Anyone know what might be causing this?
#Windows11
#Windows11
Just launched my new game Number Match – Pairs & Sum of 10 on the Microsoft Store!
A relaxing but brain‑boosting puzzle you can play anytime. Addictive, clean, and surprisingly challenging.
Free download 👇
apps.microsoft.com/detail/9NPGC...
#gamedev #MicrosoftStore #Windows
A relaxing but brain‑boosting puzzle you can play anytime. Addictive, clean, and surprisingly challenging.
Free download 👇
apps.microsoft.com/detail/9NPGC...
#gamedev #MicrosoftStore #Windows
January 20, 2026 at 10:49 AM
Just launched my new game Number Match – Pairs & Sum of 10 on the Microsoft Store!
A relaxing but brain‑boosting puzzle you can play anytime. Addictive, clean, and surprisingly challenging.
Free download 👇
apps.microsoft.com/detail/9NPGC...
#gamedev #MicrosoftStore #Windows
A relaxing but brain‑boosting puzzle you can play anytime. Addictive, clean, and surprisingly challenging.
Free download 👇
apps.microsoft.com/detail/9NPGC...
#gamedev #MicrosoftStore #Windows
Reposted by Fons Sonnemans
Feeling grateful today — my apps have now passed 6 million downloads on the Microsoft Store. Some titles are still going strong, others lived their full life back in the Windows Phone era, but the journey continues to inspire me to build new things.
#gamedev #windows #MicrosoftStore #uwp #xaml
#gamedev #windows #MicrosoftStore #uwp #xaml
January 14, 2026 at 11:25 AM
Feeling grateful today — my apps have now passed 6 million downloads on the Microsoft Store. Some titles are still going strong, others lived their full life back in the Windows Phone era, but the journey continues to inspire me to build new things.
#gamedev #windows #MicrosoftStore #uwp #xaml
#gamedev #windows #MicrosoftStore #uwp #xaml
Feeling grateful today — my apps have now passed 6 million downloads on the Microsoft Store. Some titles are still going strong, others lived their full life back in the Windows Phone era, but the journey continues to inspire me to build new things.
#gamedev #windows #MicrosoftStore #uwp #xaml
#gamedev #windows #MicrosoftStore #uwp #xaml
January 14, 2026 at 11:25 AM
Feeling grateful today — my apps have now passed 6 million downloads on the Microsoft Store. Some titles are still going strong, others lived their full life back in the Windows Phone era, but the journey continues to inspire me to build new things.
#gamedev #windows #MicrosoftStore #uwp #xaml
#gamedev #windows #MicrosoftStore #uwp #xaml
Reposted by Fons Sonnemans
Blogged: The Windows File Explorer replacement, File Pilot, is awesome
andrewlock.net/windows-expl...
In this post I describe my experience with the Windows File Explorer replacement, File Pilot. It's blazingly fast, feature rich, and has hotkeys everywhere
andrewlock.net/windows-expl...
In this post I describe my experience with the Windows File Explorer replacement, File Pilot. It's blazingly fast, feature rich, and has hotkeys everywhere
The Windows File Explorer replacement, File Pilot, is awesome
In this post I describe my experience with the Windows File Explorer replacement, File Pilot. It's blazingly fast, feature rich, and has hotkeys everywhere
andrewlock.net
January 13, 2026 at 7:45 PM
Blogged: The Windows File Explorer replacement, File Pilot, is awesome
andrewlock.net/windows-expl...
In this post I describe my experience with the Windows File Explorer replacement, File Pilot. It's blazingly fast, feature rich, and has hotkeys everywhere
andrewlock.net/windows-expl...
In this post I describe my experience with the Windows File Explorer replacement, File Pilot. It's blazingly fast, feature rich, and has hotkeys everywhere
My Surface tablet is acting weird: many apps don’t show the Min/Max/Close buttons. Some apps (Office, Edge, Notepad, Photos, Snipping Tool) are fine, but others like Settings, Store, Calculator, and Clock have none. Anyone know what might be causing this?
#Windows11
#Windows11
January 12, 2026 at 4:34 PM
My Surface tablet is acting weird: many apps don’t show the Min/Max/Close buttons. Some apps (Office, Edge, Notepad, Photos, Snipping Tool) are fine, but others like Settings, Store, Calculator, and Clock have none. Anyone know what might be causing this?
#Windows11
#Windows11
Reposted by Fons Sonnemans
🦙📢 It's been an amazing celebration of #XAMLStudio v2 these last couple of weeks. 🎊 And so #WindowsDev to culminate it all, I'd like to announce that the project is now open-sourced! A seed project in the @dotnetfdn 🎉 Read all about this journey here: devblogs.microsoft.com/ifdef-window...
XAML Studio is now Open Sourced - #ifdef Windows
XAML Studio is now open sourced! It's a WinUI developer tool for rapid prototyping with XAML before integrating in a Visual Studio project.
devblogs.microsoft.com
January 6, 2026 at 7:16 PM
🦙📢 It's been an amazing celebration of #XAMLStudio v2 these last couple of weeks. 🎊 And so #WindowsDev to culminate it all, I'd like to announce that the project is now open-sourced! A seed project in the @dotnetfdn 🎉 Read all about this journey here: devblogs.microsoft.com/ifdef-window...
Reposted by Fons Sonnemans
Are your .NET 10 Framework Dependent (not self-contained) EXEs 5x larger than they were on .NET 9?
While building the unpackaged binaries for Text Grab I couldn't understand why the build of --self-contained false was not producing EXEs that were any smaller than --self-contained true. Copilot and…
While building the unpackaged binaries for Text Grab I couldn't understand why the build of --self-contained false was not producing EXEs that were any smaller than --self-contained true. Copilot and…
Are your .NET 10 Framework Dependent (not self-contained) EXEs 5x larger than they were on .NET 9?
While building the unpackaged binaries for Text Grab I couldn't understand why the build of --self-contained false was not producing EXEs that were any smaller than --self-contained true. Copilot and Claude were not helpful so I did some searching and could not find the answer... until I searched GitHub and found several open issues discussing. According to this issue…
joefinapps.com
December 26, 2025 at 8:35 PM
Are your .NET 10 Framework Dependent (not self-contained) EXEs 5x larger than they were on .NET 9?
While building the unpackaged binaries for Text Grab I couldn't understand why the build of --self-contained false was not producing EXEs that were any smaller than --self-contained true. Copilot and…
While building the unpackaged binaries for Text Grab I couldn't understand why the build of --self-contained false was not producing EXEs that were any smaller than --self-contained true. Copilot and…
Reposted by Fons Sonnemans
On the first day of Christmas my true love sent to me 🦙🍐🎄 A Llama in a #FluentUI #XAML Tree… 🦙🍐🎄 Happy Holidays! We're back for a classic twist to preview the upcoming 2026 #XAMLStudio v2 w/ #12DaysOfXAML! Now with a new Fluent coat 🧥! #WindowsDev 🦙🍐🎄
December 25, 2025 at 6:01 PM
On the first day of Christmas my true love sent to me 🦙🍐🎄 A Llama in a #FluentUI #XAML Tree… 🦙🍐🎄 Happy Holidays! We're back for a classic twist to preview the upcoming 2026 #XAMLStudio v2 w/ #12DaysOfXAML! Now with a new Fluent coat 🧥! #WindowsDev 🦙🍐🎄
Reposted by Fons Sonnemans
December 24, 2025 at 6:40 AM
Reposted by Fons Sonnemans
Are you struggling to build well-designed (open-source or closed source) libraries that are distributed over NuGet.org or Azure DevOps Artifacts, then check out my .NET Library Starter Kit.
It contains everything I've learned from maintaining libraries with millions of downloads.
It contains everything I've learned from maintaining libraries with millions of downloads.
December 17, 2025 at 6:24 AM
Are you struggling to build well-designed (open-source or closed source) libraries that are distributed over NuGet.org or Azure DevOps Artifacts, then check out my .NET Library Starter Kit.
It contains everything I've learned from maintaining libraries with millions of downloads.
It contains everything I've learned from maintaining libraries with millions of downloads.
Reposted by Fons Sonnemans
So You Want To Speak At Software Conferences? : dylanbeattie.net
An article from dylanbeattie.net
dylanbeattie.net
December 13, 2025 at 11:44 AM
Working on a C# Source generator for non nullable properties. It generates partial properties which throw an ArgumentNullException when the value is set to null.
Would you use this?
#csharp14 #dotnet #sourcegenerator
Would you use this?
#csharp14 #dotnet #sourcegenerator
December 8, 2025 at 6:10 PM
Working on a C# Source generator for non nullable properties. It generates partial properties which throw an ArgumentNullException when the value is set to null.
Would you use this?
#csharp14 #dotnet #sourcegenerator
Would you use this?
#csharp14 #dotnet #sourcegenerator