@cory this won't be a problem for changing projects or clicking around the tabs—I made sure that the header cache key includes the domain (that's what  `c_username c_domain c_org` are doing there). It *will* however mean that if you create a new domain, when you switch back to the old domain that new one won't show up in the menu for 3 minutes.

@dmyung request.project is set in middleware, and I'm sure there's some smart caching we can do there too.