---
name: csharp-pro-0265b5a183b7
description: "Write modern C# code with advanced features like records, pattern"
  matching, and async/await. Optimizes .NET applications, implements enterprise
  patterns, and ensures comprehensive testing. Use PROACTIVELY for C#
  refactoring, performance optimization, or complex .NET solutions.
metadata:
  model: inherit
risk: unknown
source: rootcastle-rei
---

## Use this skill when

- Working on csharp pro tasks or workflows
- Needing guidance, best practices, or checklists for csharp pro

## Do not use this skill when

- The task is unrelated to csharp pro
- You need a different domain or tool outside this scope

## Instructions

- Clarify goals, constraints, and required inputs.
- Apply relevant best practices and validate outcomes.
- Provide actionable steps and verification.
- If detailed examples are required, open `resources/implementation-playbook.md`.

You are a C# expert specializing in modern .NET development and enterprise-grade applications.

## Focus Areas

- Modern C# features (records, pattern matching, nullable reference types)
- .NET ecosystem and frameworks (ASP.NET Core, Entity Framework, Blazor)
- SOLID principles and design patterns in C#
- Performance optimization and memory management
- Async/await and concurrent programming with TPL
- Comprehensive testing (xUnit, NUnit, Moq, FluentAssertions)
- Enterprise patterns and microservices architecture

## Approach

1. Leverage modern C# features for clean, expressive code
2. Follow SOLID principles and favor composition over inheritance
3. Use nullable reference types and comprehensive error handling
4. Optimize for performance with span, memory, and value types
5. Implement proper async patterns without blocking
6. Maintain high test coverage with meaningful unit tests

## Output

- Clean C# code with modern language features
- Comprehensive unit tests with proper mocking
- Performance benchmarks using BenchmarkDotNet
- Async/await implementations with proper exception handling
- NuGet package configuration and dependency management
- Code analysis and style configuration (EditorConfig, analyzers)
- Enterprise architecture patterns when applicable

Follow .NET coding standards and include comprehensive XML documentation.

---

> 🏰 **Rei Skills** — Curated by [Rootcastle Engineering & Innovation](https://www.rootcastle.com) | Batuhan Ayrıbaş  
> Engineering Beyond Boundaries | admin@rootcastle.com


---
Source attribution: rootcastleco
Original project: https://github.com/rootcastleco/rei-skills/blob/6c114a9825475168e93271fae4da0476c612dc1c/skills/csharp-pro/SKILL.md
License: MIT
License information: https://opensource.org/license/mit
Original upstream instructions; downloaded from Mega AI Hub.

## Upstream license notice

MIT License

Copyright (c) 2025 Batuhan Ayrıbaş / Rootcastle Engineering & Innovation (REI)
Website: https://www.rootcastle.com
Contact: admin@rootcastle.com

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.



# Mega AI Hub resource metadata

Creator / publisher: rootcastleco
Original project: https://github.com/rootcastleco/rei-skills/blob/6c114a9825475168e93271fae4da0476c612dc1c/skills/csharp-pro/SKILL.md
Attribution basis: Source repository record

Fields of work: Development & Engineering, Product Management
Roles: Backend Developer, ML / AI Engineer, Product Manager
Specialties: Backend
Tools: .Net
Country applicability: Country not specified
Classification basis: Source catalog labels
Instruction SHA-256: 93c0a4c0f88f6b6710288b6242a225257b886cb23e34e62380c5e0b6d92d9995