C# Digest
C# Digest
ASP.NET cookies breaking after IIS restarts? Rick Strahl explains why encryption keys regenerate and how to fix it. Also: .NET 8 and 9 both hit end of support November 2026 — time to move to .NET 10.
EF Core's missing upsert finally gets a proper fix — raw T-SQL MERGE or BulkMerge both work, but always set a business key or records silently duplicate. Also: a version mismatch made dotnet publish deploy an empty package while showing green.
The Outbox Pattern saves messages to your database in the same transaction as business data, then a background job publishes them — no lost events on crash. Also: .NET 10 now prunes redundant NuGet packages, cutting false vulnerability warnings by 70% and restore times by half.
.NET 11 brings the biggest update to `System.Diagnostics.Process` in years, adding deadlock-free output capture and `KillOnParentExit`. EF Core 11 trims split queries, cutting execution time by ~9% and memory use by ~10%.
.NET's messy naming history is actually a survival story — Microsoft rebuilt it from scratch to stay relevant in a Linux and cloud world. Also: HybridCache in .NET 9 quietly solves cache stampedes and multi-server consistency with one simple API.
C# 16 is redesigning the `unsafe` keyword so every unsafe operation must appear in an explicit block with documented caller obligations — making risky code visible instead of hidden. Also worth reading: why factory patterns in ASP.NET often just shuffle complexity around, and how state machines can manage real-world workflows like Uber's trip lifecycle.
C# 15 finally brings union types after years of requests. Also worth reading: .NET 11 adds Zstandard compression with a new ZstandardStream API, offering fast, efficient compression with ASP.NET Core integration and dictionary support for small files.
Real-time driver tracking in .NET using Redis GEO and SignalR — handling millions of GPS updates with low latency. Plus, a .NET 11 fix finally surfaces background service crashes instead of hiding them as clean shutdowns.
Discriminated unions finally land in .NET 11, letting functions return multiple result types with compiler-checked handling. Also worth reading: validate config at startup with IValidateOptions to catch missing values before your app accepts traffic.
Two-layer caching in .NET can cut response times from seconds to under a millisecond. Also worth reading: ASP.NET Core cookies can silently break auth in production, and C# 15 union types now enforce exhaustive pattern matching at build time.
SIMD lets a CPU scan 32 bytes at once, making it possible to build a CSV parser that finds field boundaries in one pass and only decodes text on demand — beating most C# parsers in benchmarks. Also: Output Cache in ASP.NET can skip your database entirely on repeat requests, with Redis support for multi-instance apps.
Copilot merged 535 of 878 pull requests in the .NET runtime after the team tuned its setup. Architectural tests can enforce design rules automatically, catching structural drift before it builds up. Health checks that test real dependencies help pinpoint failures fast.
Microsoft's GUI frameworks have shifted so many times—Win32, WPF, UWP, WinUI—that developers never had a stable path. Also: C# 15 brings union types that clean up error handling, and EF Core's bulk delete/update methods that skip loading rows entirely.
PgVector brings vector search into PostgreSQL, so you skip a dedicated database entirely. Pair it with .NET Aspire and Ollama to generate and query embeddings by cosine similarity. TUnit now embeds OpenTelemetry traces inside test reports, showing exactly what your app did during a failing test.
Unhandled .NET exceptions can leak stack traces and database paths to attackers. Adrian shows how to lock that down without losing observability. Also: how validation in ASP.NET evolved from a UI trick to a core system boundary.
LINQ is getting a FullJoin method — returns all elements from both sides, even with no match. Also: migrating from .NET Framework 4.x to .NET 10 hits real edge cases; DeeDee lists what breaks and why it matters early in planning.
Vertical Slice Architecture can cause code duplication — the fix is knowing what to share and what to keep separate. Also: how fencing tokens stop stale nodes from corrupting data in distributed systems, and how Towerborne went offline using .NET Native AOT to ship a serverless DLL across three platforms.
Async doesn't make work faster — it just frees threads. If your database gets 1,000 queries, it still gets 1,000. A hidden ASP.NET MVC bug silently dropped stricter permission filters with no warning, creating a real security gap.
This issue explores advanced .NET techniques, from solving cache invalidation with Redis to efficient bulk reading with EF Core. Plus, discover cleaner switch expressions in C# and runtime method source retrieval.
This issue covers vertical slice architecture in .NET, the new runtime async improvements, differences between readonly and immutable collections, getting started with Hangfire for scheduling, and optimizing ASP.NET Core APIs with pagination and sorting.