C# 15 Unions, PDF APIs, EF Core and Tracing
Coverage includes union types, ASP.NET Core PDF invoices, EF Core pitfalls and temporal queries, Aspire, resilience testing, and OpenTelemetry tracing.
Jasen's top three picks
- 1 How to Convert HTML to PDF in C# (.NET 10 Guide)
codewithmukesh.com
Practical and refreshingly specific: page breaks, repeating headers, currency formatting, and queuing are the details that make PDF generation production-worthy.
- 2 What's the coolest thing coming in the next version of C#?
youtube.com
If union types land as described, they could clean up a lot of awkward result modeling in everyday C# code.
- 3 Unions are here | Union types in C#
medium.com
Worth reading alongside the official preview notes so you get both the pitch and the tradeoffs.
Editor's note
I kept this one nicely mixed on purpose: language evolution, data access gotchas, observability, architecture, and a few practical web topics. The C# 15 union type coverage is the obvious headliner, but I also liked the EF ValueGeneratedOnAdd warning because it exposes a subtle bug that can waste hours. The HTML-to-PDF invoice walkthrough is another useful, concrete piece for anyone shipping real ASP.NET Core endpoints.
Today's articles
How to Convert HTML to PDF in C# (.NET 10 Guide)
codewithmukesh.com
Convert HTML to PDF in C# with .NET 10. Build a real invoice endpoint with page breaks, repeating table headers, culture-aware currency and a render queue.
Topics: ASP.NET Core .NET 10 Web API
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What's the coolest thing coming in the next version of C#?
youtube.com
Union types. Mads Torgersen explains how C# will let you model a closed set of unrelated types, create union values from them, and switch over them in a fully strongly typed way. It lands in C# 15 thi...
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Unions are here | Union types in C#
medium.com
.NET 11 is finally getting union types. If you’re interested in what they’re worth or what’s wrong with them, let’s go under the hood.
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Beware of ValueGeneratedOnAdd when using EF
josef.codes
How a self-generated GUID had EF marking my brand-new claims as Modified instead of Added, and the one line of config that fixed it.
Topics: EF Core SQL Server
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Abstractions via Interfaces: Decoupling External Services from Business Logic
medium.com
Abstraction is the bridge that allows your core application logic to interact with databases and external services without becoming…
Topics: Clean Architecture Design Patterns
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A field guide to .NET data formats
csharpdigest.net
different data formats each have their own query language
Topics: Newtonsoft.Json System.Text.Json
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.NET Aspire 13.5 Interaction Service: Building Interactive Distributed Apps
c-sharpcorner.com
Learn how .NET Aspire 13.5 Interaction Service enables interactive distributed applications with file inputs, progress dialogs, commands, and dashboard interactions.
Topics: .NET Aspire
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Migrating from Polly to Carom
medium.com
First, the disclosure: Carom is my library. Read everything below knowing that, and check the claims yourself. All of them are checkable. Continue reading on CodeToDeploy »
Topics: Performance
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Distributed Tracing in ASP.NET Core: From HTTP to the Queue with OpenTelemetry
medium.com
OpenTelemetry gets the HTTP half of a distributed trace right automatically: two services, one trace, zero manual wiring. The interesting…
Topics: ASP.NET Core OpenTelemetry
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Pipeline Pattern: A Simple Real-World Example
c-sharpcorner.com
When an application needs to perform several steps for the same request, putting everything into one large method can quickly make the code hard to understand and maintain. The Pipeline Pattern is a s...
Topics: Design Patterns
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ASP.NET Core 11 Form Validation: Testing Static SSR Under Concurrent Requests
c-sharpcorner.com
Test ASP.NET Core 11 form validation with Static SSR under concurrent requests and evaluate validation behavior, throughput, latency, and server performance.
Topics: ASP.NET Core .NET 10
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How Uno Platform uses .NET, MCP, and AI to build high quality apps
devblogs.microsoft.com
This is a guest post by Sam Basu. Sam is a technologist, author, speaker, Microsoft MVP and Developer Advocate for Uno Platform. If you've spent any time building software in the last couple of years,...
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What If Every API Failed Today? Testing Resilience with Microsoft Dev Proxy
c-sharpcorner.com
Learn how to use Microsoft Dev Proxy to simulate API failures, 503 errors, rate limiting, delays, and unexpected responses, helping .NET developers test application resilience before production.
Topics: ASP.NET Core Performance
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Building Agentic QA Pipelines with Browser Automation and .NET
c-sharpcorner.com
Learn how to build agentic QA pipelines with Playwright for .NET and AI agents, including browser automation, agent memory, tool control, execution limits, and testing best practices.
Topics: OpenAI Unit Testing
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We built a modular CMS and deliberately did not make the modules plugins
baryodev.medium.com
BarakoCMS is a .NET headless CMS with thirteen optional modules: accounting, semantic search, feature flags, file storage, social sign-in…
Topics: Authentication Clean Architecture
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Explore new features available in C# 15 preview
devblogs.microsoft.com
C# 15 will ship with .NET 11 in November. All the new features are available in .NET 11 preview 7 for you to try now. C# 15 adds union types, closed hierarchies, the first preview of an updated unsafe...
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PostgreSQL 19 Beta 3: Testing Temporal Table Queries with EF Core
c-sharpcorner.com
Explore PostgreSQL 19 temporal table capabilities with EF Core and test temporal queries, historical data access, performance, and .NET integration.
Topics: EF Core PostgreSQL
Read articleOptimizing Core Web Vitals and Technical Performance in ASP.NET Core Applications
c-sharpcorner.com
Learn how to optimize Core Web Vitals and technical performance in ASP.NET Core applications. This developer guide covers response compression, static asset caching, and layout shift fixes.
Topics: ASP.NET Core Performance
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