Daily DevOps & .NET - Where Code Meets Culture

Opinionated .NET, Azure and DevOps engineering. Hard-won lessons from production, no tutorials.

TimeProvider Test Patterns That Hold Up in CI and Production

Published on 6/23/26 5:00 pm by Martin Stühmer

FakeTimeProvider gives you a clock you control. That solves the easy 30%. The hard part is everything that interacts with that clock: async callbacks, PeriodicTimer, CancellationTokenSource.CancelAfter, BackgroundService loops, and DI lifetime traps that turn deterministic bugs into apparently flaky tests.

Standardize or Drift: One Defaults Package for All Your Solutions

Published on 6/19/26 8:45 am by Martin Stühmer

Directory.Build.props drift is the quiet tax every multi-repo .NET org pays. NetEvolve.Defaults ships MSBuild properties, .editorconfig, NuGet Audit, and ten Roslyn diagnostics as a private-asset NuGet package. Bump the version once, every repo gets the upgrade.

.NET 11: The STS Release With C# 15 Union Types and Runtime-Async

Published on 6/16/26 5:00 pm by Martin Stühmer

STS releases are supposed to be quiet bridges to the next LTS. .NET 11 is not. The union keyword landed in Preview 2, runtime-async is now the default for the BCL and ASP.NET Core shared framework, System.Diagnostics.Process ships a major overhaul, and EF Core gains approximate vector search against SQL Server 2025. All facts sourced from the .NET repositories.

TUnit.Mocks: No Castle, No Reflection, No Drama

Published on 6/11/26 5:00 pm by Martin Stühmer

Most .NET test projects rely on NSubstitute and Castle.DynamicProxy. That foundation is cracking: NativeAOT breaks it, trimming strips it, cold-start costs accumulate. TUnit.Mocks takes a different route: a source generator emits typed mocks at compile time, IService.Mock() (or Mock.Of<T>()) is the entry point, runtime reflection is gone.

The Codebase Doesn’t Know You Quit

Published on 6/9/26 5:00 pm by Martin Stühmer

The first four parts of this series treated legacy as something between me and myself: Past Self leaving code for Future Self, with an AI in the middle. That framing is incomplete. Code outlives employment, not just memory. The companies I worked for have forgotten most of what I did there. The repositories haven’t. This is the fifth part of the Code as Legacy series, about the legacy you leave when you’re not around to defend it.