.NET
The cheat sheet++ — how .NET works, from language basics to infrastructure.
C# Language
Runtime & Internals
Design Patterns
Ecosystem & Infrastructure
DI lifetimes & captive dependenciesintermediate
Singleton, scoped, transient — what actually happens per request, and the captive-dependency bug that ignores all three.
The middleware pipelineintermediate
ASP.NET Core is a Russian doll of RequestDelegates — how the pipeline is built, why order matters, and where things belong.