There are many ways to compose deferrables, primarily by grouping several of them together into something which is also a deferrable. See the em-scenario gem fo

There are many ways to compose deferrables, primarily by grouping several of them together into something which is also a deferrable. See the em-scenario gem for examples: https://github.com/athoune/em-scenario https://github.com/athoune/em-scenario Note: I still think this approach sucks. V8 provides a really awesome shared-nothing multithreading scheme via web workers. It's just nobody uses them.