@async: Defer Even More! - Matt Mahoney, Meta

Session description

@defer allows you to specify which parts of your operation are urgent, and which can be delayed. However, there is still a contract with @defer: all your data will always be returned, at some later point. This poses a problem for certain classes of product: if only 10% of your operation will ever be on consumed, but you don't know exactly which 10% that will be, defer can introduce substantial hidden costs. To improve performance and reduce compute costs, Meta created @async to ensure products only ask for data when it's needed.