@bitter-oil-46081 is jotting down an FAQ to cover this question more thoroughly. This should be posted soon,
@bitter-oil-46081 can you reply back here with a URL?
The quick answer is that the backend provider has been built to be pluggable, but that we only have two implementations at the moment. (See
https://github.com/pulumi/pulumi/blob/master/pkg/backend/backend.go.) We do have on-premise-style hosting plans for our commercial
pulumi.com, but am guessing you'd be more interested in the pluggable backend.