The docs say that RethinkDB is a requirement. Is anyone maintaining RethinkDB in a sustainable way at this point now that they've shut down? Seems questionable to rely on it for infrastructure if nobody is on the hook to keep it viable and updated.
RethinkDB now maintained by community. If it something will be bad with it, we'll change it to something. I guess we'll add ability to support custom databases by choice a bit later.
