We can all remember facing callback hell... even if we wished we could forget. Traditionally, asynchronous code in JavaScript was handled by nesting callbacks, which gets pretty messy when you have to deal with complex workflows! Years later, ES6 arrives to save us from ugly code and bringing us the tools we need to deal with asynchronous code cleanly and easily! So let us discover those tools during a live coding session, where we will be incrementally improving an ugly legacy codebase – certainly developed by someone who hasn't attended this talk! – by using promises, generators and coroutines! We will also see what's coming in JavaScript with the async / await syntax and the traps to avoid when using them. Jordane Grenat Web Application Developer and Craftsman. Passionated about web technologies, I am really interested about the JavaScript ecosystem (new EcmaScript versions, SPA frameworks, tooling, ...) [GVZ-8755]