I personally used a semaphore for that. You create a semaphore with an initial count of MAX_REQS_PER_SECOND, create WORKER_COUNT of looping "worker" tasks that

I personally used a semaphore for that. You create a semaphore with an initial count of MAX_REQS_PER_SECOND, create WORKER_COUNT of looping "worker" tasks that each call WaitAsync() on that semaphore before doing request (and don't call Release() after request is done), plus a separate task that does either Sleep(100); Release(MAX_REQS_PER_SECOND / 10); or Sleep(1000 * WORKER_COUNT / MAX_REQS_PER_SECOND); Release(WORKER_COUNT); in a loop, depending on what numbers make more sense.