Chaining Promises

• .then callbacks can be synchronous or return another Promise
• If the .then callback returns a Promise, the next .then will wait until the returned promise finishes
• This collapsing helps make asynchronous code much easier to follow
• You don't need nested callbacks. Can orchestrate everything in one place

delay(1000)
    .then(() => console.log("Hi"))
    .then(() => delay(1000))
    .then(() => console.log("I'm"))
    .then(() => delay(1000))
    .then(() => console.log("Ryan"))