Do programming languages still matter to your AI coding agent teammate? Evidence at scale from chess engines (opens in new tab)

Frontier coding agents now promise end-to-end authorship of complete software systems. Two empirical questions follow: can AI coding-agent teammates program in any target language, including ones with no comparable prior open-source artefact? If so, does language choice still shape the artefact, and along which dimensions? We study both through a polyglot case study built around chess engines: non-trivial multi-component systems that admit a hie...