Generally when I’ve successfully advocated for new languages or tools at work, it’s been by gradually introducing the language in newer and fairly self-containe

Generally when I’ve successfully advocated for new languages or tools at work, it’s been by gradually introducing the language in newer and fairly self-contained projects where the risk is relatively low. This provides a safe space to explore all the concerns you just mentioned without compromising any working code. If you have some interest in Rust, that’s what I’d personally recommend instead of migrating an existing service to a different language.