To continue, I'd say this is where [`-flattenMap:`](https://github.com/ReactiveCocoa/ReactiveCocoa/blob/8cb404a9be99f9b3515bc16b6874ce85fee37b0b/ReactiveCocoaFramework/ReactiveCocoa/RACStream.h#L98-L125) gets a chance to shine. This [blog post](http://www.techsfo.com/blog/2013/08/managing-nested-asynchronous-callbacks-in-objective-c-using-reactive-cocoa/) and [Stack Overflow](http://stackoverflow.com/a/15827396) give a good demonstration.