Amusingly, in an environment with a level of parallelism, the above code poses few problems even if http.get/put are synchronous & blocking. A scheduler handles

Amusingly, in an environment with a level of parallelism, the above code poses few problems even if http.get/put are synchronous & blocking. A scheduler handles a bunch of blocked threads perfectly fine, and the series of calls per job aren't inefficient when executed in series. We hit pain points when we can't have parallelism in our programs, and are forced to make elegant the work-arounds intended to unclog those programs.