What's proper here? I work in a TS shop, 95% of our in-house CLIs are in written in TS and to date it has been an issue... once a year? If we really need better than TS has to offer then sure, go write some Rust or Go, but most of the time we get a lot of added benefit from the fact that literally any developer in the company can bugfix or extend the CLIs without assistance from these teams.