This is not the first company switching from a a dynamic language to Go. Python and Ruby are great for getting started quick but when you scale up you need a workhorse like Go. Nothing too fancy but nice features that give the language a modern touch. I guess Github and more will pick it up soon.
I find blanket statements about performance like this to be pretty meaningless. I develop both Python and Go as well, and honestly performance is not the number one criteria I've used in deciding which to use for a project. I ask questions like "Are there existing Python packages that tip the scale", "If I expect to need real concurrency, would it be IO bound or CPU bound", "Do I want to make the tradeoff of the increased stability of static typing in exchange for more man-hours on this project?" Things like that.
It's perfectly fine to be using more than one tool. Starting with Python can be a good idea because of the rapid development and turnaround while experimenting. If Python ends up being fast enough, that's great. But if it doesn't, then it's nice to have this new language which is almost native speed and still fun to write, unlike Java or C++.
So in your opinion, languages are ranked in order of "performance"? See, in my experience, it just doesn't work that way. Sometimes it does, sure, but it's not a rule that I can use in my life.
Seems like it would be nice if I could just say "I need this done fast, I'll use Python" or "I need 'performance' so I'll use Golang"
And to be fair, many benchmarks in Go don't perform nearly as fast as C or even the JVM. Go has gotten faster with each point release but again, these sorts of raw performance benchmarks aren't really good for anything except providing an apples-to-apples comparison. Because it's not usually a question of building the same exact app in the same exact way in one language or another.
