https://app.pluralsight.com/library/courses/advanced-javascript/

Async Patterns

Callbacks

• an async pattern - can lead to "callback hell" - callback nesting or continuation style
• callback/continuation leads to inversion of control (e.g. consider calling a third-party lib and passing it a callback)

Solving Callback Problems

• separate callbacks
• node-style / error-first style
• nested-callback tasks

Generators

• ...

Promises pattern

• McDonalds order metaphor
• "continuation events" metaphor
• handing back a promise "un-inverted" the inversion of control of callbacks
• Promise are built-in as of ES6