Dennis Doomen
@dennisdoomen.com
Microsoft MVP | Coding Architect | .NET Tech Lead | .NET & C# | TypeScript | Fluent Assertions Author | International Speaker | Occasional Trainer | React & VueJS | Event Sourcing Veteran | DDD Designer | TDD Practitioner | Clean Code Writer
Soon, at a conference or event near you...
January 21, 2026 at 3:53 PM
Soon, at a conference or event near you...
Although #Mockly's fluent API provides a lot of power to build complicated HTTP mocks, sometimes you just want to provide a full URL with wildcards. Well, that's supported too.
Check out the documentation at github.com/dennisdoomen...
Check out the documentation at github.com/dennisdoomen...
January 20, 2026 at 12:20 PM
Although #Mockly's fluent API provides a lot of power to build complicated HTTP mocks, sometimes you just want to provide a full URL with wildcards. Well, that's supported too.
Check out the documentation at github.com/dennisdoomen...
Check out the documentation at github.com/dennisdoomen...
One of the most annoying aspects of a lot of HTTP mocking libraries in .NET is that it takes way too much time to figure out why the mock wasn't invoked correctly. E.g. Did I use the wrong path? The wrong query maybe? Did I make a mistake in the order? Especially with the more complicated...
January 12, 2026 at 7:27 PM
One of the most annoying aspects of a lot of HTTP mocking libraries in .NET is that it takes way too much time to figure out why the mock wasn't invoked correctly. E.g. Did I use the wrong path? The wrong query maybe? Did I make a mistake in the order? Especially with the more complicated...
Looking forward to what 2026 will bring for me in terms of conferences. But I can already confirm you will find me in Redmond, Stockholm, Athens, Krakow and Mannheim.
January 7, 2026 at 7:35 AM
Looking forward to what 2026 will bring for me in terms of conferences. But I can already confirm you will find me in Redmond, Stockholm, Athens, Krakow and Mannheim.
I know it's cheesy at best, but I couldn't resist myself. So this is what 2025 looked like for me.
⏬ 150 million downloads of my projects
💰1 open-source project got commercial
⭐4 new open-source projects with 24K downloads in total...
⏬ 150 million downloads of my projects
💰1 open-source project got commercial
⭐4 new open-source projects with 24K downloads in total...
January 5, 2026 at 3:30 PM
I know it's cheesy at best, but I couldn't resist myself. So this is what 2025 looked like for me.
⏬ 150 million downloads of my projects
💰1 open-source project got commercial
⭐4 new open-source projects with 24K downloads in total...
⏬ 150 million downloads of my projects
💰1 open-source project got commercial
⭐4 new open-source projects with 24K downloads in total...
I don't know why, but somehow 2025 has been the year were I suddenly felt energized to create a whole bunch of new open-source projects. In fact, I started 5 (!) new projects in the last 15 months, next to continuing the development of FluentAssertions (and we're at 8.8 now). (cont'd)
December 30, 2025 at 3:19 PM
I don't know why, but somehow 2025 has been the year were I suddenly felt energized to create a whole bunch of new open-source projects. In fact, I started 5 (!) new projects in the last 15 months, next to continuing the development of FluentAssertions (and we're at 8.8 now). (cont'd)
I've released Mockly 1.1:
🔧Add RespondsWith overloads for HttpContent instances
🔧Add IResponseBuilder interface for test data builder integration
🔧Fixed a bug where a custom port number wasn't always honored
🔧Throwing an exception from RespondsWith is tracked as a request
🔧Add RespondsWith overloads for HttpContent instances
🔧Add IResponseBuilder interface for test data builder integration
🔧Fixed a bug where a custom port number wasn't always honored
🔧Throwing an exception from RespondsWith is tracked as a request
December 24, 2025 at 6:20 AM
I've released Mockly 1.1:
🔧Add RespondsWith overloads for HttpContent instances
🔧Add IResponseBuilder interface for test data builder integration
🔧Fixed a bug where a custom port number wasn't always honored
🔧Throwing an exception from RespondsWith is tracked as a request
🔧Add RespondsWith overloads for HttpContent instances
🔧Add IResponseBuilder interface for test data builder integration
🔧Fixed a bug where a custom port number wasn't always honored
🔧Throwing an exception from RespondsWith is tracked as a request
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.
600 million downloads.... That's what happened during the weekend...
And yes, v7 is still fully open-source, free and fully supported with important bug fixes. And if you need all the power of v8, it's only $14.95 per year per developer.
And yes, v7 is still fully open-source, free and fully supported with important bug fixes. And if you need all the power of v8, it's only $14.95 per year per developer.
December 15, 2025 at 5:24 PM
600 million downloads.... That's what happened during the weekend...
And yes, v7 is still fully open-source, free and fully supported with important bug fixes. And if you need all the power of v8, it's only $14.95 per year per developer.
And yes, v7 is still fully open-source, free and fully supported with important bug fixes. And if you need all the power of v8, it's only $14.95 per year per developer.
Are C# developers still using the "event" keyword anymore? I haven't used it in a decade or so.
December 12, 2025 at 4:50 PM
Are C# developers still using the "event" keyword anymore? I haven't used it in a decade or so.
When an unexpected request occurs and there are multiple configured HTTP mocks, Mockly helps you diagnose that by reporting the closest matching mock (method, scheme/host/path/query) so you can quickly see what to adjust in your setup. Check out Mockly at github.com/dennisdoomen...
December 9, 2025 at 6:36 PM
When an unexpected request occurs and there are multiple configured HTTP mocks, Mockly helps you diagnose that by reporting the closest matching mock (method, scheme/host/path/query) so you can quickly see what to adjust in your setup. Check out Mockly at github.com/dennisdoomen...
The last couple of weeks, I've been working on a new open-source project called #Mockly, a mocking library for the .NET HttpClient. It provides a fluent API for configuring HTTP request mocks, capturing request details, and asserting on HTTP (cont'd)
December 8, 2025 at 2:31 PM
The last couple of weeks, I've been working on a new open-source project called #Mockly, a mocking library for the .NET HttpClient. It provides a fluent API for configuring HTTP request mocks, capturing request details, and asserting on HTTP (cont'd)
I'm starting this week with a big smile. Not only because I had a great weekend, but mostly because I genuinely enjoyed being at the #DDC2025 conference in #Cologne. It's the perfect conference to wrap up a long year of conference talks. Why is that? Because it's organized by...
December 1, 2025 at 4:58 PM
Now we need the "await" syntax for C# properties as well.
November 15, 2025 at 11:15 AM
Now we need the "await" syntax for C# properties as well.
You know the music of a video game is a masterpiece when you listen to it on Spotify and it makes you want to go to that world again. I have that with "The Witcher 3", "The Last of Us", and the two "Horizon" games. What about you?
Jared Longing GIF
ALT: Jared Longing GIF
media.tenor.com
November 14, 2025 at 2:22 PM
You know the music of a video game is a masterpiece when you listen to it on Spotify and it makes you want to go to that world again. I have that with "The Witcher 3", "The Last of Us", and the two "Horizon" games. What about you?
Cool. In the latest version of @microsoftteams.bsky.social you can finally use : to type emojis inline.
November 13, 2025 at 1:28 PM
Cool. In the latest version of @microsoftteams.bsky.social you can finally use : to type emojis inline.
Last night, Microsoft launched .NET 10 and C# 14. For that occasion, #SDN, Sopra Steria and @roelant.info organized a launch event at their offices in Utrecht. I myself, @codewithanjuli.bsky.social, Beatriz del Saz and Selmir Aljic joined a panel hosted by Henry Been to discuss the news and what...
November 12, 2025 at 2:45 PM
Last night, Microsoft launched .NET 10 and C# 14. For that occasion, #SDN, Sopra Steria and @roelant.info organized a launch event at their offices in Utrecht. I myself, @codewithanjuli.bsky.social, Beatriz del Saz and Selmir Aljic joined a panel hosted by Henry Been to discuss the news and what...
During the weekend, I've shipped another version of my "dotnet new" starter kit for generating super-professional .NET solutions for building open-source or internal libraries. Check it out at github.com/dennisdoomen...
November 10, 2025 at 3:47 PM
During the weekend, I've shipped another version of my "dotnet new" starter kit for generating super-professional .NET solutions for building open-source or internal libraries. Check it out at github.com/dennisdoomen...
Op 11 nov kun je vanaf 16:30 bij Sopra Steria live the lancering van .NET 10 bijwonen gevolgd door een panel met Henry Been, @codewithanjuli.bsky.social, Beatriz del Saz, Selmir Aljic en ik. Ook praat @hexmaster.nl ons bij over #Aspire. Inclusief eten. Inschrijven op www.meetup.com/nl-NL/future...
November 7, 2025 at 7:56 AM
Op 11 nov kun je vanaf 16:30 bij Sopra Steria live the lancering van .NET 10 bijwonen gevolgd door een panel met Henry Been, @codewithanjuli.bsky.social, Beatriz del Saz, Selmir Aljic en ik. Ook praat @hexmaster.nl ons bij over #Aspire. Inclusief eten. Inschrijven op www.meetup.com/nl-NL/future...
I've just released PackageGuard 2.0, my little open-source tool for keeping grip on your open-source packages, that adds support for NPM, PNPM and Yarn package.json files.
Try it out and let me know if you find anything that needs improving at github.com/dennisdoomen...
Try it out and let me know if you find anything that needs improving at github.com/dennisdoomen...
November 6, 2025 at 3:52 PM
I've just released PackageGuard 2.0, my little open-source tool for keeping grip on your open-source packages, that adds support for NPM, PNPM and Yarn package.json files.
Try it out and let me know if you find anything that needs improving at github.com/dennisdoomen...
Try it out and let me know if you find anything that needs improving at github.com/dennisdoomen...
This week, I'll go on stage at the DevOps track of DevCon 2025 in Bucharest, Romania. This time I'll talk about Boundary-Driven Development, my term for thoroughly understanding and adjusting the internal boundaries of your codebase to optimize maintainability. Find me on Thursday at 14:00.
November 4, 2025 at 12:24 PM
This week, I'll go on stage at the DevOps track of DevCon 2025 in Bucharest, Romania. This time I'll talk about Boundary-Driven Development, my term for thoroughly understanding and adjusting the internal boundaries of your codebase to optimize maintainability. Find me on Thursday at 14:00.
Grateful to speak at @techorama.bsky.social—the biggest & coolest #Benelux conference! Shared 40+ ways to reduce complexity & coupling with a packed 8:30 crowd. Massive thanks to the amazing team & community. If you weren’t there—fix that next year!
October 29, 2025 at 4:46 PM
Grateful to speak at @techorama.bsky.social—the biggest & coolest #Benelux conference! Shared 40+ ways to reduce complexity & coupling with a packed 8:30 crowd. Massive thanks to the amazing team & community. If you weren’t there—fix that next year!
Tomorrow at 8:30, I'll be kicking off the second day of @techorama.bsky.social with 40 tips & tricks to keep your C# code base in check. Then, at 11:15, I'll join #TechoramaTV to talk about the topic of development.
Will I see you there? techorama.nl/speakers/spe...
Will I see you there? techorama.nl/speakers/spe...
October 28, 2025 at 2:10 PM
Tomorrow at 8:30, I'll be kicking off the second day of @techorama.bsky.social with 40 tips & tricks to keep your C# code base in check. Then, at 11:15, I'll join #TechoramaTV to talk about the topic of development.
Will I see you there? techorama.nl/speakers/spe...
Will I see you there? techorama.nl/speakers/spe...
✈️ Last week, I attended the second edition of the @hellostavanger.no conference in the beautiful seaside town of #Stavanger, Norway. As this conference is organized by speakers, it means it ran smooth as oil and addresses everything speakers run into at other conferences.
October 27, 2025 at 2:28 PM
✈️ Last week, I attended the second edition of the @hellostavanger.no conference in the beautiful seaside town of #Stavanger, Norway. As this conference is organized by speakers, it means it ran smooth as oil and addresses everything speakers run into at other conferences.
Fluent Assertions 8.8 was released yesterday. Check out the details at xceed.com/blog/all/flu...
October 24, 2025 at 1:58 PM
Fluent Assertions 8.8 was released yesterday. Check out the details at xceed.com/blog/all/flu...