This is a situation where one of the biggest (maybe the biggest) chat applications has a bit of code that's run "every time a message is sent and every time a m

This is a situation where one of the biggest (maybe the biggest) chat applications has a bit of code that's run "every time a message is sent and every time a message is read". In this instance Go's GC pauses were causing performance issues, they rewrote it in Rust with very good results. This doesn't mean that your application needs to be written in Rust because Go "isn't performant" =)