it's a tool language in my opinion. Fast compile times, reduced language set, good concurrency model. So I would say it's a language for services or tools where concurrency is utilized.
Docker is Go for example, but you can actually do a lot of things.
One of the main "features" of go is no objects but powerful interface compositions.
That's my idea of the language, but I guess you can do a lot of other things, people wrote compiler in it, proxies, limetext (sublime like), webhooks, blogs (hugo), ....