Software developer/architect .NET solutions, Microsoft MVP, public speaker, teacher, first aid instructor, open source developer

Tilburg, The Netherlands
Joined June 2009
Johan Smarius retweeted
Your AI agent: “Trust me.” 🤖 You: “Cite the docs.” 📚😎 Microsoft Learn MCP Server gives MCP-compatible assistants access to current Microsoft guidance via doc search, docs fetch + code sample search. 🔌 ▶️ msft.it/6019aself
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This looks promising. I cannot make it to the presentation but I hope it will come online. Will experiment and share my thoughts about it.
AI agents are writing more code. How can developers ensure that code is correct? Microsoft Research’s Proof-Driven Development (PDD) Kit explores a more rigorous approach: it translates a developer’s intent into a formal specification, then uses formal verification to prove that generated code meets it. PDD Kit works with Verus for Rust and is integrated with @GitHubNext’s Chopin, bringing formal methods into an AI-assisted development workflow for teams. See the work in action at @github Universe, Oct. 28–29, 2026.
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Johan Smarius retweeted
The agent changed your payment retry logic. The tests pass. The diff looks clean. Before you merge, put a breakpoint in Rider and watch it retry. Three attempts, or thirty?
An agent writes the code now. Do you still need an IDE? You do if you want to understand and verify what the agent did. 🎥 In our new video, we talk about the role of an IDE now that humans aren't the only ones working on the code. youtu.be/AHFGMkzrfwM
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Johan Smarius retweeted
Better yet, try it yourself. The fastest way to get your hands on JetBrains Air: 1⃣Download Rider 2026.3 EAP: jb.gg/rd-263-eap 2⃣Look for the Air icon or press ⌘2 (Ctrl+2). Let us know what you think in the comments!
Holy moly, we’ve seen a lot of interest in JetBrains Air since the announcement! -Air in IDEs: for developers -Air Teams: for team leads & engineering managers -Air Governance: for CTOs & engineering directors Here’s how to try these things: Links below 🧵
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Johan Smarius retweeted
Introducing Microsoft-Decision-1 Our model for fast decision-making that delivers top performance in latency and quality on structured decision tasks to outperform both LLMs and other decision models. commandline.microsoft.com/mi…
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Johan Smarius retweeted
One agent is fixing a bug, another is writing tests, and you’re working on something else. Sounds familiar? With JetBrains Air in Rider, you can do all that (and even more!) inside your IDE using any of 50+ supported agents. Finally! Try it in the EAP now jb.gg/rd-263-eap.
We've reimagined JetBrains IDEs to become the ultimate agentic workbench. Air is an open hub for agents inside your IDE: -Any agents to run (Claude, Codex & many more) -Agents are more efficient with IDE intelligence -Free Junie Lite agent bundled -Cloud runs via Air Teams ⬇️
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Johan Smarius retweeted
Visualize Data Structures in VS Code 🤯 If you work with data structures, check out the Debug Visualizer extension for VS Code. It lets you visualize your data while debugging so you can actually watch algorithms and data structures change as your code runs. In this example, see a linked list grow node by node and watch QuickSort move values into sorted order. A great tool for learning data structures, understanding algorithms, and debugging complex code. #VSCode #Programming #Coding #DataStructures #Developer
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Johan Smarius retweeted
A little while ago, I asked what features and tweaks you wanted to see coming to Visual Studio. One of them was a file system view alongside Solution Explorer. This is now available in the Insiders build
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Johan Smarius retweeted
As we all enter wave 2 of the "great AI psychosis" with these new models - just a few reminders... 1. You need to sleep every night. I know that you're not tired and you don't want to, but you look like crap. Go to bed. 2. Cheetos is not a meal. Neither is 3, 5-layer burritos delivered via door dash for the 4th time in 3 days. Your intestines have been trying to get your attention for the last 48 hours. 3. Try and shower at least every other day. If you can't because "omg what is this going to look like when the agent is finished!!!" then at least keep a bottle of perfume/cologne on the desk. Do it so things don't seem completely out of control when the welfare check comes. 4. If you have a family then you need to speak to them at least once a day. Try and make eye contact and try to do it without prompting your agent at the same time. Sleep helps a lot with this. 5. Being away from your desk does not count if you are just going to get on your phone to keep prompting. This is especially true if you're trying to date. It's hard to attract someone when you're in a sweaty AI fever dream. The cologne/perfume comes in clutch here. 6. Most importantly, whatever it is that you think that you have created that is the most incredible thing ever, I can almost assure you it is not. I realize that to you it looks like you have changed software forever, but in fact 20 other people have already built what you have and it's already live on the internet and your agent probably copied from their site anyway. Good luck. God speed. I'll see you on the other side.
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Johan Smarius retweeted
Get a quick explanation of a commit from Visual Studio. Go to Git > Manage Branches > Double Click a Commit to Open details > ✨ Explain Pro-tip: Expand/Collapse the commit details (highlighted with purple) for more screen real state.
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This is a great addition to the GitHub Copilot app. Most customers I work with use Azure DevOps. I will definitely start using this today.
The GitHub Copilot app now supports Azure DevOps! You can now view your work - including assigned issues and PRs - and kick off sessions directly from those artifacts. Grab it from new Customize tab in the app :)
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Johan Smarius retweeted
.NET devs: make debugging fun again 🔧🔥 Breakpoints, step-through flow, state inspection, logging + tracing — all in one tight Learn module. 👉 Jump in: buff.ly/NM473Me
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Johan Smarius retweeted
We gotta stop inventing words that make simple concepts hard to understand. Loop = Scheduled task Graph = Subagents
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Johan Smarius retweeted
Go for the gold and get a certification before the end of the month 🏅
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Johan Smarius retweeted
Introducing the Open Source Maintenance Fee for Polly thepollyproject.org/2026/07/…
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Johan Smarius retweeted
“Generate unit tests” leaves a lot unsaid. A new open-source test agent learns the repo, framework, and test command before writing tests. It completed 140/152 benchmark tasks vs 120/152 for stock Copilot. devblogs.microsoft.com/dotne…
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Johan Smarius retweeted
JetBrains Junie is one of the most cost-efficient coding agents on the market today. Internally, we see Junie power users consuming 2–4× fewer tokens than with Codex or Claude Code—while achieving comparable productivity. Here are a few simple tips to get the most out of it 🧵
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