This is low prio, but nice to try: since the CPU in prod for Sync is at most 30%, we can try to add more gunicorn servers behind nginx. In theory, there's a limited number of workers that can spare the same socket, so having two Gunicorn instances on a separate socket and nginx that handles the load balancing --very easy config in nginx-- could raise the maximum number of requests one box can handle.
(if there's room in memory of course)
is this still required?
we're doing fine with gevent/async workers
OK. Verifying as a WontFix.