Engineer production-grade .NET and C# — modern language features, ASP.NET Core APIs, clean and vertical-slice architecture, EF Core data access, async and concurrency, dependency injection, testing, observability, resilience, security, and performance. Use whenever writing, designing, reviewing, or debugging .NET, C#, ASP.NET Core, Web APIs, microservices, or backend services, even when the user only says build an API, a service, or a feature.
