It removes the API design, versioning, etc. pain which is probably huge in an organization as large as facebook. But there's still going to be a decent bit of

It removes the API design, versioning, etc. pain which is probably huge in an organization as large as facebook. But there's still going to be a decent bit of backend tuning which in my experience is the hard part (unless the organization is so dysfunctional new API version design meetings descend into a hostage exchange).