The example screams "Premature Optimization". What if fetch_*() weren't async function (e.g. because doing CPU heavy work)? The Rust Code would look just like

The example screams "Premature Optimization". What if fetch_*() weren't async function (e.g. because doing CPU heavy work)? The Rust Code would look just like the Golang code, except you'll now need the wrapper code do make them async.