Yes, C# is faster than Rust

Overview

David Heinemeier Hansson (DHH) had an open-source Campfire chat app, originally built with Ruby on Rails, ported to Rust with the help of AI agents. The Rust version was reported to be roughly 20 times faster than the Ruby version.

Another developer later ported Campfire to C# and .NET. In the benchmark discussed, the C# version was reported to be about twice as fast as the Rust version. However, the presenter notes that the Rust and C# results came from different computers, so they are not a controlled or definitive comparison.

Implementation and Review

The presenter ran the C# app and confirmed that it worked, with memory usage under 100 MB. The version shown used .NET 11 RC2.

The port uses minimal APIs and endpoint mappings, along with Razor Slices, which compile CSHTML views into classes. It also uses a custom “Front End Result” library built on top of minimal APIs.

The presenter’s main architectural criticism is that the endpoint mappings are difficult to navigate in a large, single codebase. They would have preferred a conventional .NET MVC project. In their view, the custom library and minimal-API approach may be reasonable for an AI-generated port, but they would not recommend it for a production rewrite.

Broader Argument

The video argues that Microsoft and the .NET team should showcase .NET’s performance more prominently and provide clear, simple MVC samples. It contrasts this with other prominent projects being rewritten in Go or Rust.

Type of Content

No step-by-step guide is presented. The video informally reviews the Campfire port, its benchmark claims, and its implementation.

Speakers and Sources

Ed Andersen provides the commentary and code review. The benchmark figures are attributed to the developer who created the C# port, while DHH is cited for the original Rails-to-Rust project.