I've had agents implement and optimize the Campfire web app in Elixir, Go, Rust

A software leader reports having used autonomous agents to reimplement and optimize the Campfire web app in Elixir, Go, and Rust, and found Ruby to be the slowest of the four. He emphasizes that Ruby’s performance trade-off was previously acceptable because it delivered large gains in developer productivity and joy, but that calculus changes once agents are generating and validating code instead of humans reading and maintaining it. He linked to a repository demonstrating the experiments and published performance comparisons to illustrate the point.

He argues that language choice must be reconsidered now that code may be authored by agents: runtime speed matters more when human review drops off, even though languages like Rust bring other costs such as slower compile times. The claim sparked immediate pushback from others noting surprising performance gaps - one commenter questioned the large difference between Go and Rust - highlighting an active debate about which languages balance execution speed, developer ergonomics, and toolchain overhead in an era of automated code generation.