.NETPro #20: Clean Architecture With ASP.NET Core 10, Modernizing .NET Applications With GitHub Copilot, Observability in .NET With OpenTelemetry, What's New in C# 14 and F# 10, and More...
🌍 Actionable .NET tips, updates, and community insights at a glance
How’s .NET 10 treating you so far?
Whether you’re enjoying a smooth upgrade or untangling project files, you’ve likely caught some of the community buzz around the new Copilot modernization tool. Some developers miss the trusty free Upgrade Assistant, while others are beginning to embrace the AI-powered shift. The .NET team is listening closely, rolling out fixes and even restoring the legacy option for those who prefer it. Curious what the new tool actually does? We’ve got an expert walkthrough inside.
You’ll also find a guide on why companies that say .NET moves too fast might soon be budgeting for post-EOL support. And of course, we’ve rounded up all the key .NET 10 updates, plus expert insights to help you make the most of them.
Take a look at today’s top picks:
➡️ C# 14 delivers extension members and significant updates for modern development
➡️ .NET 10 adds native post-quantum cryptography with four new algorithms
➡️ F# 10 delivers refined language updates, improved tooling, and performance enhancements
➡️ Supercharge Your Test Coverage with GitHub Copilot Testing for .NET
➡️ Andrew Lock argues that organizations unhappy with .NET’s rapid changes may need paid post-EOL support if they can’t upgrade in time
➡️ Learn how to modernize .NET applications with GitHub Copilot Agent Mode
➡️ Yulia Samoylova explains why observability is vital for modern .NET apps and how APM tools help teams stay ahead of issues
Keep reading, and when you’re done, drop us a note about what you enjoyed and how we can make the next edition more helpful.
Cheers!
Adrija Mitra
Editor-in-Chief
Missed Our Last Three Special Issues?
Parts 1, 2 and 3 of our ongoing special series, Partial Types and Members: Breaking Apart and Reassembling C# Classes with Mark J. Price, are live now!
If you haven’t checked them out yet, now’s the perfect time to catch up! Explore the series here: [Part 1], [Part 2], and [Part 3].
📰 What’s Happening in .NET!
The latest .NET breakthroughs are here. Haven’t explored them yet? Dive in now!
➡️ Introducing C# 14: The release of C# 14 alongside .NET 10 introduces extension members that allow you to define extension properties, operators and static extensions, enabling cleaner and more expressive code. It also brings productivity and performance enhancements by unlocking features like implicit spans, the field keyword, and modifiers on lambda parameters.
➡️ Reinventing how .NET Builds and Ships (Again): .NET 10 introduces the Unified Build system, bringing a Virtual Monolithic Repository and streamlined vertical build process to the product stack. This re-architecture targets faster and more predictable end-to-end builds, dropping core build times to under 4 hours and improving overall flexibility and release cadence.
➡️ Introducing F# 10: F# 10 arrives with .NET 10 and brings refined language improvements, stronger tooling support, and performance enhancements. Key additions include scoped warning suppression through #warnon and #nowarn directives, access modifiers on auto property accessors, struct-based ValueOption parameters, and more consistent syntax across computation expressions.
➡️ Post-Quantum Cryptography in .NET: .NET 10 introduces native support for post-quantum cryptography, adding four new algorithms (ML-KEM, ML-DSA, SLH-DSA and Composite ML-DSA) within the System.Security.Cryptography namespace to strengthen application security in the quantum-era.
➡️ .NET and .NET Framework November 2025 servicing releases updates: The November 2025 servicing update for .NET 8 (8.0.22) and .NET 9 (9.0.11) is now live with non-security fixes across installers, container images and Linux packages to deliver enhanced stability, improved performance and simplified deployment for developers and operations teams.
⏱️ Time for Some Hands-On .NET
Don’t miss this edition’s spotlight guide!
This guide by McKenna Barlow introduces the new GitHub Copilot testing for .NET feature in Visual Studio, showing how it automates test creation, building and execution for C# projects across entire solutions using xUnit, NUnit or MSTest.
Why it’s worth exploring
It helps you boost efficiency in generating and running unit tests, ensures consistency with project standards, and keeps your focus on code quality rather than manual test writing.
What you need before diving in
The latest Visual Studio 2026 Insiders Build, C# code, and a GitHub Copilot license
Explore the complete guide now!
Missed Parts 1, 2 and 3 of our ongoing special series Partial Types and Members: Breaking Apart and Reassembling C# Classes with Mark J. Price? Don’t worry, we’ve got you covered! Check out [Part 1], [Part 2], and [Part 3].
🧑🏼💻 What .NET Experts Are Talking About
Inside the minds of .NET pros: Real-world experience, real insights!
➡️ A step-by-step guide to modernizing .NET applications with GitHub Copilot agent mode: This guide by Mika Dumont shows how to modernize your .NET applications using GitHub Copilot Agent Mode. It covers analyzing your project, generating an upgrade plan, applying updates and preparing for cloud deployment, all with the aim of simplifying what is usually a tedious migration process.
➡️ Clean Architecture with ASP.NET Core 10: In this session, Ardalis (Steve Smith) shows how ASP.NET Core offers stronger support for clean, testable and maintainable architectures than earlier frameworks. He explains the principles behind effective project and solution organization, how to structure projects for loosely coupled code, and how to refactor existing solutions toward this architecture.
➡️ Companies complaining .NET moves too fast should just pay for post-EOL support: In this post, Andrew Lock highlights the shift to shorter .NET support lifecycles, with Standard-Term releases supported for two years and Long-Term releases for three. He explains why organizations that cannot upgrade promptly may need to rely on paid post end of life support to stay secure and compliant.
➡️ Beyond Monitoring: Observability in .NET with OpenTelemetry: In this session, Yulia Samoylova explains why observability is vital for modern .NET apps and how APM tools help teams stay ahead of issues. She covers how logs, metrics, and traces work together, practical instrumentation options, the growing role of OpenTelemetry, and how commercial platforms streamline troubleshooting and performance optimization.
➡️ .NET Conf 2025 changed my opinion about .NET: In this video, Ed Andersen breaks down key themes from the .NET Conf 2025 keynote, highlighting the continued push behind Aspire, the growing focus on Copilot, shifting mentions of Blazor and containers, and the sharp drop in MAUI visibility. He reviews the trends, the data, and what they suggest for .NET’s direction.
Missed Parts 1, 2 and 3 of our ongoing special series Partial Types and Members: Breaking Apart and Reassembling C# Classes with Mark J. Price?
Don’t worry, we’ve got you covered! Check out [Part 1], [Part 2], and [Part 3].
And That’s a Wrap 🎬
Thanks for diving in. I hope this issue sparked an idea or two that could help fuel your next big project.
Got a minute? We’d love your feedback—just take this quick 1-min survey to help us improve future editions.
Keep learning, keep building, and we’ll see you next time!