Dennis Doomen
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dennisdoomen.com
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
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
December 24, 2025 at 6:20 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.
December 17, 2025 at 6:24 AM
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.
December 15, 2025 at 5:24 PM
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
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
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
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
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
Cool. In the latest version of @microsoftteams.bsky.social you can finally use : to type emojis inline.
November 13, 2025 at 1:28 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...
November 12, 2025 at 2:45 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...
November 10, 2025 at 3:47 PM
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
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...
November 6, 2025 at 3:52 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.
November 4, 2025 at 12:24 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!
October 29, 2025 at 4:46 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...
October 28, 2025 at 2:10 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.
October 27, 2025 at 2:28 PM
Fluent Assertions 8.8 was released yesterday. Check out the details at xceed.com/blog/all/flu...
October 24, 2025 at 1:58 PM
Yeah. We finally have threads in @microsoftteams.bsky.social. Happy to see that the product team has been learning from Slack after all.
October 22, 2025 at 10:52 AM
Last weekend, I shipped release 1.7 of Pathy, a tiny library for fluently building and using paths without binary dependencies. It comes with two improvements.

1. Preventing the debugger from stepping in Pathy's code
2. Using the .. syntax for representing a parent path
October 21, 2025 at 2:25 PM
I watched "Tron: Ares" in IMAX 3D last night. Not the best story every written, but definitely an absolutely amazing experience I've never had before in a cinema. Do yourself a favor and find a cinema with true 4K lasers and an IMAX 3D screening.
October 20, 2025 at 1:55 PM
Suppose you want some kind of non-intrusive time tracking for developers to see how much time is spend on features (on a high-level), what would you recommend? It should give sufficient info for managers without infuriating the dev teams.
October 16, 2025 at 1:43 PM
For the past 15 years, I've been the author of Fluent Assertions, an open-source project with over half a billion downloads. In January, we made the decision to commercialize it—a move I still stand by, but one that didn’t come without controversy. This gave me renewed...
October 15, 2025 at 1:01 PM
During the weekend, I've shipped a small increment to Pathy, a no-dependencies library for fluently building paths and working with files and directories. Version 1.6 adds a bunch of nice improvements that I needed myself ;-)

* LastWriteTimeUtc property to ChainablePath...
October 14, 2025 at 5:37 PM