I should definitely make a macro at this point:

Callback paradigm has not been used in node development for 3-4 years at this point.

    return someHttpCall()
    .then(response => someOtherHttpCall(response))
    // Do 2 async operations in Parallel:
    .then(response => Promise.join(
      someCacheThing(response),
      someDBThing(response)
    ))
    .spread((cacheResponse, dbResponse) => sendBackToClient());

This isn't callback hell. Without creating or managing threads, I have established serial as well as an example of branched concurrent logic that is entirely nonblocking. Every promise is handled as a try catch, so error handling can be done at the end of the chain with a single `.catch`.

Clustered express application puts the performance well within what you would expect from Go/Phoenix, all of which are operating at an order of magnitude above Python/Ruby.