I don't see how this is exceptionally surprising. You rewrote an application from one of the slowest scripted languages out there to a new, fast systems level programming language.
Maybe it just underscores the slowness of Ruby.
Your main site is down. Giving off 502s.
Best in class!
Nice article on rewriting something: it focuses on the need for the rewrite, and on an analysis done beforehand to get an idea of what to focus on. The rewrite is driven by a successful business, in other words.
I'm a bit curious what was so slow about the Ruby code, as it sounds like it was just doing 'managing' rather than actual heavy-duty processing, which no, it is not good at.
Erlang sounds like it would have been a good fit too, although it's not quite as performant as Go.