Den Delimarsky
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den.dev
Den Delimarsky
@den.dev
✍️ Blogger: https://den.dev
🫛 Podcaster: https://theworkitem.com
🤖 Core Maintainer: https://modelcontextprotocol.io
🪴 Product Engineer
🎨 Aspiring Digital Artist
There's very few people that I can instantly recommend as "OMG, if they are hiring - you want to work there."

@seldo.com is, without a doubt, one such person.

You WANT to work on their team.
Okay folks, it's time: I'm hiring!

Looking for 5(!) developer relations engineers across the world! Our company is remote-first but this role involves in-person appearances at events so although you don't need to work in a specific office we are focusing our search in specific metro areas:
Developer Relations Engineer
San Francisco, CA
job-boards.greenhouse.io
November 10, 2025 at 10:09 PM
A discussion with one of my research colleagues and @simonwillison.net led me to write this down.

"Full Stack Person" sounds like a mouthful, but IMO captures well the idea of becoming a well-rounded technologist.

den.dev/blog/full-st...
November 7, 2025 at 10:28 PM
Reposted by Den Delimarsky
How do you build quality software with LLMs?

@den.dev talks on .NET Rocks at www.dotnetrocks.com/details/1974 about GitHub Spec Kit, which uses specifications to help LLMs generate better code!
.NET Rocks!
.NET Rocks! is a weekly talk show for anyone interested in programming on the Microsoft .NET platform. The shows range from introductory information to hardcore geekiness.
www.dotnetrocks.com
October 30, 2025 at 3:02 PM
Reposted by Den Delimarsky
Catching @den.dev’s talk on MCPs @github.com Universe 👀 #mcp #agenticai
October 28, 2025 at 9:34 PM
Guess who's back on The Work Item! It's @shirleywu.studio!

Listen to full show
www.youtube.com/watch?v=0O35...
October 21, 2025 at 1:27 AM
Client ID Metadata Documents just got accepted into the MCP spec 🥳

Much better DevEx for both client and server developers, and much less painful than Dynamic Client Registration (DCR).
October 16, 2025 at 7:03 PM
I used Spec Kit to build a Mauna Kea observatory camera tracker 🌠

In the process, had to write a full guide for Spec Kit, because why not 🤷

Read
den.dev/blog/github-...
October 13, 2025 at 6:59 PM
We just published a whopping many-page-long authorization guide for MCP on the official MCP website.

Weekend reading? 🤩

modelcontextprotocol.io/docs/tutoria...
October 12, 2025 at 7:41 PM
September 5, 2025 at 6:29 PM
We're working on a fun little experiment that helps bring some structure to LLM-powered software development - it's all about spec-driven development (SDD) ✨

I wrote a post on the @github.com blog that talks about the practices and a (minimalistic) toolchain for this: github.blog/ai-and-ml/ge...
September 4, 2025 at 7:09 PM
New podcast episode drop ✨

This one I looked forward to releasing - it's with none other than @shirleywu.studio!

You might know her from the MULTIPLE hit visualizations that took over your social feeds (including one for Hamilton), and so much more.

Full show 👉 theworkitem.com/episodes/dat...
August 14, 2025 at 4:59 PM
Check this out! Just last week, I talked at MCP Developer Days with some awesome folks from Arcade.dev about MCP server security and how to protect them when it's not just humans working with them ✨
dot.net .NET @dot.net · Aug 8
🔐 Building secure AI agents? In this MCP Dev Days session replay, we deep dive on advanced MCP server security—OAuth 2.1, token validation, and defending against confused deputy attacks. #AIsecurity
🎥 msft.it/63322sKX9M
August 8, 2025 at 9:38 PM
Reposted by Den Delimarsky
It's Friday, delegate your work to coding agent and start your weekend early
August 8, 2025 at 4:46 PM
A new REALLY COOL role in our division at Microsoft - Principal Technical Program Manager!

🥹 Collab with me (benefit or drawback, depending on how you look at it)
✨ Work on cutting-edge AI dev tools
👻 Craft ways to synthesize feedback

🧙‍♀️ Role: jobs.careers.microsoft.com/global/en/jo...
August 8, 2025 at 1:52 AM
Reposted by Den Delimarsky
We heard you like Opus..
August 5, 2025 at 7:48 PM
You know what makes me happy about this list? Auth 😊

One of the big questions that comes up when folks want to adopt MCP is "How do I allow my users to auth against protected resources?"
Results are in!

🧩Prompts > 🔐MCP OAuth > 📚Resources > 🧠Sampling

- Prompts: modelcontextprotocol.io/docs/concept...
- MCP OAuth: modelcontextprotocol.io/specificatio...
- Resources: modelcontextprotocol.io/docs/concept...
- Sampling: modelcontextprotocol.io/docs/concept...

Time to cook!
July 31, 2025 at 11:00 PM
New podcast episode with @lennpryor.bsky.social just dropped ✨

Biggest takeaway - we're all thinking wrong about our careers.

Check full episode out 👉 theworkitem.com/episodes/bui...
July 29, 2025 at 6:27 AM
Reposted by Den Delimarsky
Can You Build Agent2Agent Communication on MCP?
Yes.

I wrote an article about how you can compose some of the recent features within MCP( resumable streams, elicitation, sampling, and notifications ) to implement long running agents (as tools):
devblogs.microsoft.com/blog/can-you...
July 24, 2025 at 10:25 PM
Reposted by Den Delimarsky
🚨 Live in 30 minutes! Hosted by Anthropic, catch the webinar with Burke Holland and Harald Kirschner from the VS Code team: "Building the future of AI coding with MCP in VS Code and Claude"

Register here: www.anthropic.com/webinars/fut...
July 24, 2025 at 4:31 PM
Reposted by Den Delimarsky
Hey folks, if you are working with Model Context Protocol in C#, you should check out the features in our latest SDK release. I wrote about them in the .NET Blog. Check it out!
devblogs.microsoft.com/dotnet/mcp-c...
#dotnet
MCP C# SDK Gets Major Update: Support for Protocol Version 2025-06-18 - .NET Blog
The MCP C# SDK has been updated to support the latest Model Context Protocol specification (2025-06-18), bringing structured tool output, elicitation support, enhanced security, and more to .NET devel...
devblogs.microsoft.com
July 23, 2025 at 2:42 AM
Reposted by Den Delimarsky
MCP Dev Days is only a week away! Don't miss this two-day virtual event dedicated to MCP. You'll hear from the community, see live demos, dive deep into implementation, and so much more.

Register now: aka.ms/MCPDevDays
July 22, 2025 at 6:18 PM
Check this magic out ✨

If you are using @vscode.dev Insiders, you get to plug in remote MCP servers that do not support Dynamic Client Registration (DCR) and still be able to work with them - you'll just need to enter client details 😁

One of the ways we're making the dev experience butter-smooth!
July 21, 2025 at 12:36 AM
MCP now has an official governance and stewardship model ✨

modelcontextprotocol.io/community/go...
July 15, 2025 at 1:36 AM
The year of Linux on the desktop.
July 12, 2025 at 5:42 PM
Kind of neat that @vscode.dev now supports MCP elicitations - directly asking users for schematized input rather than relying on prompts 💫

Quick overview and demo 👉 den.dev/blog/vscode-...
July 7, 2025 at 3:59 PM