csharp-dotnet-review

name	csharp-dotnet-review
description	Review .NET/C# code: ASP.NET Core, EF Core, Minimal APIs, Azure patterns and performance
triggers	{"frameworks":["dotnet","aspnet","efcore","blazor"],"file-patterns":["**/*.cs","**/*.csproj"]}
preferred-model	sonnet
min-confidence	0.4
depends-on	[]
category	code-quality
estimated-tokens	5000
tags	["csharp","dotnet","aspnet"]

C# / .NET Code Review

When to Use

• Reviewing C#/.NET code (ASP.NET Core, EF Core, Minimal APIs)
• Evaluating .NET architecture patterns (Clean Architecture, CQRS, MediatR)
• Azure service integration review

Review Checklist

Architecture & Patterns

• Clean Architecture: Domain independent of infrastructure
• Dependency Injection used throughout (no new Service())
• CQRS separation when appropriate (Commands vs Queries)
• MediatR or similar for decoupled handlers
• Repository pattern for data access abstraction
• Options pattern for configuration (IOptions<T>)

C# Best Practices

• async/await used correctly (no .Result or .Wait())
• CancellationToken propagated through async chains
• IDisposable implemented for unmanaged resources
• null handled with nullable reference types (?, ??, ?.)
• Records used for immutable DTOs
• sealed classes where inheritance not needed
• readonly for immutable fields
• Pattern matching instead of type casting

EF Core

• No N+1 queries (use .Include() or .AsSplitQuery())
• AsNoTracking() for read-only queries
• Indexes defined on frequently queried columns
• Migrations tested and reversible
• Connection pooling configured
• Query filters for soft delete / multi-tenancy

Security

• [Authorize] on all protected endpoints
• Input validation with data annotations or FluentValidation
• Anti-forgery tokens for forms
• CORS configured restrictively
• User secrets / Azure Key Vault for credentials
• No SQL string concatenation (parameterized queries)

Performance

• Response caching where appropriate
• IMemoryCache or IDistributedCache for hot data
• Minimal API for high-throughput endpoints
• System.Text.Json configured (not Newtonsoft unless needed)
• Pagination on list endpoints
• Background tasks via IHostedService / Hangfire

Output Format

## .NET Review: [Component]
**Health Score**: X/10

### Critical Issues
- [Issue with fix]

### Improvements
- [Suggestion with example]

### Architecture Notes
- [Pattern observations]