I also think it is great that Discord is using the right tool for the job. It isn't often that you need the performance gains that Rust & Tokio so pick what works best to get the job done and iterate.
> Rust is blazingly fast and memory-efficient: with no runtime or garbage collector, it can power performance-critical services, run on embedded devices, and easily integrate with other languages.
I’m not so sure they would have done the rewrite if the Go GC was performing better, and the choice of Rust seems primarily based on prior experience at the company writing performance sensitive code rather than delivering business value.