The full system is built in rails and I query and generate information on a million or so accounts and tens of millions of comments. Haven’t really hit a bottleneck yet.
Of course, Go's popularity is helped a great deal by Google using it, as well as the huge amount of devops software written in Go (docker, terraform, kubernetes). But at some point the hype for those will settle and they'll just become more tools. At the same time there'll be more and more legacy Go projects at various companies that won't be very exciting. Around about this time we'll probably see the next language start rising in popularity.
"Developer productivity" is not a myth and it does exist. But Rails is very far from the only framework that gives you that.
IMO you should seriously evaluate making your web + API gateway in either Elixir or Go, outline a migration plan and get on with it.
I think Elixir is very interesting but Phoenix still has some way to go before the ecosystem matches that of Rails. Our Gemfile.lock https://gitlab.com/gitlab-org/gitlab-ce/blob/master/Gemfile.... is more than 1000 lines!
In the end, it's your call of course. But line-count doesn't say anything about a project's complexity. Go is quite verbose but with rigorous CI, tests, code reviews and linters, teams produce pretty hardcore and good software in Go, regularly.
Another thing is that there isn't a web framework like Rails in Go. Although I'm keeping an eye on go-micro and we plan to add that as a template soon.
I am not disputing your choices. Just wanted to give you the quick and intuitive (and likely misinformed) immediate reaction that I had from the article.
Keep making GitLab awesome. <3
See https://docs.gitlab.com/ee/development/architecture.html#com... for more information on what parts are Go.