how do shortlinks work? (inside google)

I found out that inside google , shortlinks are used to navigate around to different Google services. For example:

go/mail would take you to gmail

go/docs would take you to docs

And that is entered in the 开发者_如何转开发address bar of the browser .

I'm just wondering if anyone knows how it works ? is it internal DNS mapping ?

I don't know how it does work, but I know how it could work.

Create a computer called "go". Set up DNS mapping so "ping go" does something useful.

On that computer run a web server which, when "http://go/mail" is fetched, responds with HTTP status code 302 (redirect).