Why Can Rust Be Ugly to Humans and Useful to Agents?

David Heinemeier Hansson hates reading Rust and still ships applications written in it. He calls it the ugliest programming language invented in probably the last 40 years, the opposite of Rails, and painful enough that looking at the code feels like acid in his eyes. He has written Rust anyway, and C++ as well, on vibe-coded projects of his own.

The output is why he puts up with it. Memory safety, a real systems language, and high efficiency are incredible, so Rust can be repugnant for a human to read and a wonderful platform for agentic engineering at the same time. He expects those two judgments to coexist. The agent can produce the code. He does not have to enjoy staring at it.