And once those long running jobs have reported their status back to the database, how will the client find out about that status?

Please, please, please don't say "polling". Because you've clearly missed the entire argument of the article if you say polling.

postgresql has LISTEN and NOTIFY. redis and kafka have pubsub. this is a solved problem

	▲	zknill 2 hours ago \| parent [-]
		Isn't the point that you no longer have a connection to the client? So you can be notified by the database, but you can't (with the stateless HTTP + loadbalancer design explained in the article) get that notification back to the client. Because the client isn't connected anymore; so how does the client know that there's new information?