Modern .NET Fundamentals

When to Use

• Writing or modifying any C# production code — this is the baseline skill; dotnet-aspnet, dotnet-ef-core, and dotnet-sdk-builder build on top of it, so load this skill alongside them, not instead of them
• Registering services in any IServiceCollection (ASP.NET Core, Worker Service, Console app, MAUI, library DI extension methods)
• Choosing a DI lifetime (Transient, Scoped, Singleton) or registering keyed services (since .NET 8)
• Deciding which .NET version to target — scaffolding a new project, generating a .csproj, or naming a target framework in output
• Binding configuration sections to a strongly-typed Options class
• Setting up appsettings.json, environment-specific overrides, User Secrets, or environment variables
• Adopting primary constructors, required properties, nullable reference types, or CancellationToken propagation in new code

Core Principles