JavaScript Promises — Office Chai Edition (States, Methods & Event Loop)

JavaScript Promises are one of the most misunderstood yet essential features in modern JavaScript development. Most articles explain the syntax. Very few explain: Why Promises exist How they actually behave internally Why .then() doesn’t run immediately How microtasks change execution order So let’s break it down properly. And to make it memorable, we’ll use something every startup developer understands: ☕ The 4:30 PM Office Chai Break What Is a Promise — Really? A Promise represents the eventual result of an asynchronous operation. It’s a placeholder for a value that will exist in the future. That means: A Promise starts in pending It becomes fulfilled (success) or rejected (failure) Once settled, it never changes again Think of it like ordering chai at work. You don’t get tea immediately. You get a commitment that tea will arrive later. Or maybe it won’t. That’s a Promise. ☕ The Startup Office Chai Scenario It’s 4:30 PM. Sprint is heavy. Production bug open. Everyone tired. Someone s