How does one avoid callback hell with regards to JavaScript?

Use a framework like Backbone JS to split up your code into manageable view and controller blocks.

I like to use promises (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise). They allow you to turn nested callbacks such as these: getProfileById(id, function (err, profile) { if (err) return console.error(err); getFriends(profile.friends, function (err, friends) { if (err) return console.error(err); getFriendsPosts(friends, function (err, posts) { if (err) return console.error(err); UpdateView(profile, friends, posts); }); }); }); into this: getProfileById(id) .then(getFriends) .then(getFriendsPosts) .catch(function (err) { console.error(err); }); Now, browser support is a bit dodgy at the moment, but I prefer to use https://github.com/petkaantonov/bluebird anyway. It's a promise library that offers a polyfill (back to IE7) and extra features (such as promisification: http://bluebirdjs.com/docs/features.html#promisification-on-steroids). In ES6 you can also use generator functions (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/function*), but you can't polyfill those and I haven't really tried them out outside of a few test applications. Still, nice to have a variety of choices.

Callbacks are an essential part of JS which allows asynchronicity. We should embrace them dearly. I am not an expert in JS so you may choose not to take me very seriously but please read on. So everybody can start coding in JS pretty quickly. However owning the language is really something different. It will take time and a lot of coding. I have read tons of books and have an idea on most of the complicated aspects of this language. However i have to do many years of coding before i gain reflexes and can say i am an expert, which as of today i am greatly lacking. A developer can switch from C++ to Python, yielding sort of syntax change into a more readable, maintainable scripting environment. However with JS it's not only the syntax changing. In JS the approach to handle things are somewhat different. There are things which are nonexistent in some other mainstream languages such as prototypal delegance (i won't say inheritance), no classes, natural asynchronicity built in the callback architecture, functional scopes and closures etc... To where i want to come is, anybody coding Python at the backend and switching to JS at the frontend has to switch his mindset too. This might be really annoying to many people resulting performance loss. I am sure some do it perfectly well but probably many end up with a simplistic JS regardless of how much they are good at Python. Here comes the beauty of full stack JS. I think a web app developer should primarily focus on JS to gain the experience to harness JS at it's best. I am sure callbacks are not any hell for a full stack JS developer after some time and coding since s/he can quickly see what's going on. I have seen a beautiful answer in the topic by which i want to copy here with a little bit of a touch. Considering a hypothetical language, cascaded IO requests look like this, 1 2 3 4 var a = readFileContents("a.txt"); var b = readFileContents("b.txt"); writeFileContents("ab.text", a + b); console.log("we are done"); 2nd line starts only after 1st line finishes reading from the db. This type of program halts execution till it retrieves data from readFileContents method. In node, same would be implemented as 1 2 3 4 5 6 7 readFileContents("a.txt", function (a){ readFileContents("b.txt", function (b){ writeFileContents("ab.txt", a + b, function(){ console.log("we are done"); }); }); }); you call the function readFileContents at line 1 and continue at line 8. No blocking. If you notice, our simple logic has complicated code to read, however we can write once but later on it is difficult to understand what is happening here. Yes it looks complicated but I have to say that it's all about experience to quickly see logic behind this and it's beautiful. I feel like when i felt the first time i've understood the recursive procedures of Pascal, which was many many years ago. Besides... I have noticed that nobody under this topic has ever mentioned the importance of commenting. I believe commenting in the code and in the VCS of your choice is an highly important aspect of understanding what's going on there. No? Edit: Checking up with 's answer i concluded that he has a solid point. New JS interpretations like ES6 https://developer.mozilla.org/tr/docs/Web/JavaScript/Reference/Global_Objects/Promise introduces some level of simplification to the callback structure for a human being. However then a compatibility issue arises since even the current versions of the mainstream browsers support ES6 only partially. Given that still the corporate user's un-upgradable browser is taken into account it's a big no no to touch ES6 while developing web applications. Having said that you may still develop a Git branch of your code in ES6 and then "transpile" (i have to admit, i use this word for the first time in my life) it down to ES5 by https://esnext.github.io/es6-module-transpiler/. This might be a way to avoid the so called callback hell.