In addition, you can break your program down into flows of tasks up front. Thinking about the synchronization explicitly helps too, often there is too much unn

In addition, you can break your program down into flows of tasks up front. Thinking about the synchronization explicitly helps too, often there is too much unnecessary communication. I think that the data structures used by D for message passing are the real interesting part here. Akin to not using raw pointers, don't use raw data structures to convey state updates and let the owner of that state do it themselves with a queue or some abstraction for messages.