This is a great discussion: I wonder though if we are asking the right question. Yes, absolutely language choice can play a large role in the efficiency of coding agents. The point about Rust is right: static typing provides a fast verification loop at compile time. I would argue though that the way the codebase is composed could actually generalize the concept of "easy verifiability" past the actual coding language.

For instance, if an application can be broken down into components that have a verifiable contract in how they are to be used, then an LLM can load only the relevant modules into its context and fully understand how to use them and fix them if needed. It is also easier for the LLM to verify the functionality of a component rather than the entire system.

Additionally, in an application composed of functioning components, issues are more likely to occur at the boundaries between them, which the LLM can focus on rather than having to always consider the entire application that it most likely can't load fully into its context.

A well designed componentized Python application will likely be far more efficient for modification by an LLM than a large Rust monolith.