Generate and Test C# Enterprise Code

This is a C# expert skill for modern .NET development and enterprise-grade applications, focused on modern C# features (records, pattern matching, nullable reference types), the .NET ecosystem (ASP.NET Core, Entity Framework, Blazor), SOLID principles and design patterns, performance optimization and memory management, async/await and concurrent programming with the Task Parallel Library, comprehensive testing (xUnit, NUnit, Moq, FluentAssertions), and enterprise/microservices architecture. Its approach favors composition over inheritance, nullable reference types with comprehensive error handling, performance work using Span/Memory/value types, and non-blocking async patterns throughout.

Use this skill when working on C#/.NET tasks that need modern language features, SOLID design, performance optimization, or enterprise architecture patterns applied consistently. It is not the right skill for tasks unrelated to C# or .NET, or for a different domain or tool outside this scope.

Input is a C#/.NET development task; output is clean C# code using modern language features, comprehensive unit tests with proper mocking, performance benchmarks using BenchmarkDotNet, async/await implementations with proper exception handling, NuGet package and dependency configuration, code-analysis and style configuration (EditorConfig, analyzers), and enterprise architecture patterns where applicable - following .NET coding standards with comprehensive XML documentation.

.NET developers building enterprise-grade C# applications who want modern language features, SOLID design, async correctness, and BenchmarkDotNet-backed performance work applied consistently rather than decided ad hoc per project.