PouchDB ⇆ CouchDB ⇆ Sync Gateway ⇆ Couchbase Server
However, what I thought I'd be able to do was directly sync PouchDB without needing a CouchDB intermediary, like so:
PouchDB ⇆ Sync Gateway ⇆ Couchbase Server
Alas, that approach didn't work for me — when I tried to replicate directly against sync_gateway, all it logged was a HTTP: OPTIONS /todos/ request when the web app first loaded. My wild guess would be that it may be related to the CORS setup required to get things working with a CouchDB instance, but I have no idea. Would be great to hear from anyone else who's experimenting with PouchDB + Sync Gateway!