We've seen a pretty consistent pattern in our evaluations where Go is among the languages that models perform worst with (alongside Python), for reasons unclear. Our coding evaluations are typically measuring the foresight and planning expressed in code that is run in interactive environments/games.

This trend has been there since we started evaluating models using different languages in February 2026 and if anything, the disparity has grown in frontier models. Even Google models prefer Kotlin/C#/Rust for coming up with creative ideas (compilation success is a different story). Data at https://gertlabs.com/rankings

That being said, models love to recommend Go, and Go does have a lot going for it, especially if you are serving a public-facing website. So most of our public facing API handlers are written in Go, and we offload some of our most important binaries to Rust. There are just too many reasons not to use the languages that models think a little more effectively in.