C# Developer

Purpose

When to Use

• Building C# applications with .NET 8
• Developing ASP.NET Core web APIs
• Implementing Entity Framework Core data access
• Using modern C# features (records, patterns, etc.)
• Building enterprise .NET applications
• Writing unit tests with xUnit/NUnit
• Implementing dependency injection patterns

Quick Start

• Building C# applications with .NET 8
• Developing ASP.NET Core web APIs
• Implementing Entity Framework Core data access
• Using modern C# features
• Building enterprise .NET applications

• Building cross-platform .NET MAUI apps (use dotnet-core-expert)
• Working with .NET Framework 4.8 (use dotnet-framework-4.8-expert)
• Building Windows desktop apps (use windows-app-developer)
• Azure-specific infrastructure (use azure-infra-engineer)

Decision Framework

Project Type:
├── Web API → ASP.NET Core Minimal API or Controllers
├── Web App → Blazor or Razor Pages
├── Background service → Worker Service
├── Desktop → WPF, WinUI, or MAUI
└── Library → .NET Standard or .NET 8

Data Access:
├── SQL with ORM → Entity Framework Core
├── SQL with control → Dapper
├── NoSQL → MongoDB driver or Cosmos SDK
└── Multiple DBs → Repository pattern

Core Workflows

1. ASP.NET Core API Development

1. Create project with appropriate template
2. Configure dependency injection
3. Implement domain models
4. Set up EF Core with migrations
5. Create controllers or minimal API endpoints
6. Add validation and error handling
7. Implement authentication/authorization
8. Add OpenAPI documentation

2. Entity Framework Core Setup

1. Define entity models
2. Configure DbContext
3. Set up relationships and constraints
4. Create initial migration
5. Implement repository pattern if needed
6. Add query optimization
7. Configure connection resilience

3. Testing Strategy

1. Set up xUnit or NUnit project
2. Create unit tests with mocks
3. Implement integration tests
4. Use WebApplicationFactory for API tests
5. Add test database fixtures
6. Configure CI test pipeline

Best Practices

• Use records for DTOs and immutable data
• Leverage pattern matching for cleaner code
• Use nullable reference types
• Implement IAsyncDisposable for async cleanup
• Use primary constructors in C# 12
• Configure EF Core query splitting for includes

Anti-Patterns