The .NET Insider – Issue 16

The article explains how to design and implement a robust invoice builder application using modern .NET technologies, with a strong focus on PDF generation quality, reliability, and compliance.

The article explains the Transaction Script pattern in ASP.NET Core Minimal APIs, showing how handling all logic inside a single endpoint can speed up delivery but quietly create technical debt as business rules grow. It highlights when this pattern is useful, when it becomes harmful, and how to recognize the warning signs before simple scripts turn into hard-to-maintain systems.

.NET 10 introduces key networking upgrades, including faster HTTP performance with optional certificate validation caching, a new QUERY HTTP verb for safe requests with bodies, and a modern stream-based WebSocket API that dramatically simplifies message handling. The release also improves security with public CookieException support and TLS 1.3 on macOS.

A new .NET MAUI BillingService sample shows how to implement cross-platform in-app purchases for Android, iOS/Mac Catalyst, and Windows using platform-specific APIs behind a single unified interface. The sample demonstrates clean architecture with dependency injection, MVVM, and conditional compilation, and provides a production-ready client-side solution, with guidance on platform setup and a future path toward StoreKit 2.

Microsoft Learn MCP Server integrates with GitHub Copilot to provide accurate, up-to-date Microsoft documentation and code samples directly inside your editor. It reduces hallucinations, improves context-aware code suggestions, and helps developers learn and solve problems faster without leaving their development tools.

Azure Cosmos DB is evolving into a search-native database, blurring the traditional line between OLTP databases and search systems like Elasticsearch. By building on its distributed, schema-free JSON model and highly optimized inverted index, Azure Cosmos DB now natively supports full-text search, vector similarity search, hybrid ranking, and semantic re-ranking. This convergence enables AI-first, low-latency applications to perform transactional queries and semantic search in a single system—without the overhead of maintaining separate databases and search engines.

Aspire 13.1 delivers a polished update focused on making AI coding agents first-class citizens in your workflow, alongside smoother CLI experience, smarter dashboards, improved Azure deployments, and end-to-end HTTPS support for local development.

The December 2025 servicing update refreshes .NET 10 to version 10.0.1, delivering non-security fixes across the runtime, SDK, ASP.NET Core, WinForms, Entity Framework Core, and tooling. There are no new updates for .NET Framework this month, and developers are encouraged to upgrade to the latest service release.

A practical guide to customizing Windows Terminal and boosting productivity with GitHub Copilot CLI—showing how to personalize your terminal, integrate AI assistance directly in the command line, and enhance prompts with tools like Oh My Posh for a smoother, faster developer workflow.

A concise guide showing that iOS widgets can be built professionally with .NET MAUI, combining MAUI with Xcode and Swift. The article focuses on real-world architecture, common pitfalls, and key concepts—from bundle IDs and widget lifecycles to data flow and icons—helping developers avoid fragile setups and build stable, interactive iOS widgets.

A concise introduction to a C# article series that makes Martin Fowler’s enterprise patterns explicit instead of accidental. It explains how common patterns already appear in ASP.NET applications, shows when to use or avoid them, and demonstrates how they combine into real, maintainable architectures with concrete C# code.

A concise overview of concurrency control in .NET, explaining why synchronization matters and how primitives like lock, the new .NET 9 Lock type, Semaphore, and async-friendly SemaphoreSlim help safely coordinate access to shared resources in multithreaded applications.

A practical guide to handling large file uploads and downloads in .NET using Azure Blob Storage, covering storage setup, container configuration, and safe upload strategies—highlighting why simple uploads work for small files but chunked uploads are essential for large, multi-GB files.