csharp-type-design-performance

What problem does it solve?

Designing .NET types for performance is challenging; this skill provides guidelines to minimize allocations, enable JIT devirtualization, and ensure safe, fast APIs.

Core Features & Use Cases

• Sealing classes by default to improve inlining and API clarity.
• Using readonly structs for small immutable value types.
• Preferring static pure functions to reduce state and improve testability.
• Deferring enumeration and returning immutable collections at API boundaries.

Quick Start

Command: Review a .NET type for performance improvements and propose changes to seal classes by default, use readonly structs for small value types, switch to static pure functions where possible, defer enumeration, and return immutable collections.