Actaully the pubsub part is pretty core to system overall. Basically I have a set of 'operations' modules each operating independently (gathering news, tweets, votes, stock quotes, etc). They publish that data over the pubsub system, so that all the subscribers (mostly in-memory caches) read and update accordingly.
Game events also get published through it (round end, trade placed, new round, etc)
Game events also get published through it (round end, trade placed, new round, etc)