C# Unions, Copilot Trust, and Postgres Security
A varied .NET roundup covering type-safe API contracts, debugger agents, Copilot controls, Postgres RLS, SignalR tooling, and Azure resilience.
Jasen's top three picks
- 1 LINQ and lambda expressions in C# for beginners
Round The Code
A solid practical starting point for developers who want to move beyond loops and make LINQ operators feel less magical.
- 2 The Visual Studio Debugger Agentic Workflow Gets a Test-Driven Upgrade
Microsoft Dev Blogs
The important angle here is verification: agent-assisted debugging becomes much more credible when tests define the finish line.
- 3 Can You Trust an LLM to Fix a Broken Locator?
Medium
A healthy look at using model consensus as a signal without handing an LLM unchecked control over automation.
Editor's note
I pulled together a deliberately varied set today, from approachable LINQ fundamentals to operational Azure design decisions. The ASP.NET Core unions article is particularly useful for modeling honest API contracts, while the Postgres row-level security piece is a worthwhile reminder that tenant boundaries belong in the database too.
Today's articles
LINQ and lambda expressions in C# for beginners
Round The Code
Learn LINQ and lambda expressions in C# with beginner friendly examples covering Where, Select, OrderBy, GroupBy, ToDictionary and many more LINQ methods.
Topics: C#
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The Visual Studio Debugger Agentic Workflow Gets a Test-Driven Upgrade
Microsoft Dev Blogs
A few months ago, we introduced a new guided agentic workflow in the Visual Studio Debugger Agent designed to help you move from a bug report to a verified fix without spending your morning guessing w...
Topics: Test-Driven Development Visual Studio
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Can You Trust an LLM to Fix a Broken Locator?
Medium
A measured study of multi-provider LLM consensus as a locator-healing signal — and why Automation Sandbox keeps the LLM out of the…
Topics: Security
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You Are Not Behind: Why You Are Still On .NET Framework
The Modern .NET Show
Show Notes Hey everyone, and welcome back to The Modern .NET Show; the premier .NET podcast, focusing entirely on the knowledge, tools, and frameworks that all .NET developers should have in their too...
Topics: .NET Framework
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GitHub Copilot Agent Plugins: Testing Plugin Trust Across VS Code and Copilot CLI
C# Corner
Learn how to test GitHub Copilot agent plugins across VS Code and Copilot CLI, focusing on trust, permissions, reproducibility, tool access, and security controls.
Topics: GitHub Copilot Security Visual Studio Code
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Numerics.NET with Jeffrey Sax
.NET Rocks!
So what can numerics do for you? Carl and Richard talk to Jeffrey Sax about his work building Numerics.NET, a collection of general-purpose mathematical and statistical classes built for .NET. Jeffrey...
Topics: C# Performance
Read articleHow to Build High-Performance Distributed Systems with .NET Core — By Najeeb Ullah
Medium
Building large-scale enterprise applications requires deep architectural knowledge and efficient coding practices. As a Top .NET Creator…
Topics: Design Patterns .NET Core Performance
Read articleHow Architects (Senior Devs) Choose a Database in 2026
Medium
Choosing a database is one of the most impactful decisions you make in a project. Continue reading on CodeX »
Topics: Domain-Driven Design Design Patterns
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Use C# unions and closed hierarchies in ASP.NET Core
Microsoft Dev Blogs
Sometimes an API contract says that a value can have more than one JSON type. Kubernetes has a practical example: maxUnavailable can be an absolute number, such as 2, or a percentage, such as "25%". I...
Topics: ASP.NET Core System.Text.Json Web API
Read article⚡ Code Faster in VS Code #vscode #html #vscodetips
YouTube
Emmet is a built-in tool in VS Code that helps you write code faster using short, simple shortcuts. Try it out! aka.ms/Emmet
Topics: Visual Studio Code
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.NET R&D Digest (August, 2026)
WordPress
This issue includes bits of life story, AI, C#, security, performance, Aspire, TDD, .NET and of course .NET Internals.
Topics: .NET Aspire C# Performance
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Let Postgres Enforce Tenant Isolation
Milan's .NET Weekly
EF Core query filters can be bypassed. PostgreSQL row-level security enforces tenant isolation on reads and writes, if you connect with the right database role…
Topics: EF Core PostgreSQL Security
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Building Apps That Live Inside Someone Else’s Software
Medium
What we learned building inside Reapit’s AppMarket
Topics: Design Patterns REST API
Read article🧳 Bring Your Own AI Models to GitHub Copilot in VS Code
YouTube
Use your own Azure-hosted AI models with GitHub Copilot in VS Code. See how Bring Your Own Key (BYOK) lets you connect models from Microsoft Foundry, choose which models appear in Copilot, and use the...
Topics: Azure GitHub Copilot Visual Studio Code
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The perils of binding to value types in XAML
Microsoft Dev Blogs
A colleague ran into trouble with their XAML program. They were using a FlipView control to bind to a collection, but when the user tried to navigate the FlipView using an assistive technology tool, t...
Topics: WPF
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SignalR Is Not Just a WebSocket Frame
Medium
Building the DevTools panel I wanted while debugging ASP.NET Core SignalR applications
Topics: ASP.NET Core SignalR
Read articleBuilding an End-to-End Enterprise AI Platform on Azure
YouTube
Enterprise AI systems span ingestion, embeddings, vector search, APIs, and partner integrations—often across serverless and container platforms. In this presentation, see how Contoso builds a producti...
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Two zones or three? A design framework for zone-resilient Azure workloads
Microsoft Azure
Zone resiliency isn't a single number you apply to a whole workload. The useful question isn't “how many zones?” but “how many zones does each component need to survive the loss of one?” Decide zone p...
Topics: Azure
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Agent Skills 101
YapCast – Jesse Liberty
tl;drImagine an AI assistant in your company that can write emails, check expense reports, and run CI pipeline steps — but it has every capability baked into one giant prompt. It’s slow, expensive, br...
Topics: GitHub Actions GitHub Copilot
Read articleMCP: Server, Client & Protocol at GitHub
YouTube
Sam Morrow is a co-creator of GitHub's MCP, an MCP Spec Maintainer, and Copilot client developer. Find out the latest MCP features his team are shipping on both the server and client side, as well as ...
Topics: GitHub GitHub Copilot
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How to make AI write high-quality code in .NET
C# Digest
it can write .NET code quickly, but it does not always follow your standards
Topics: C#
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