Writing complex Javascript applications comes with a unique set problems. We've run up into many different ones. Through our successes and failures we've come up with a set of patterns. These are not specific to our application but are when you're building a certain class of application. You don't need if you're building Todos. I'll present patterns used in Javascript and things you can do from the API perspective to make developing easier and more testable. These cover topics such as DOM manipulation, resource separation, data loading, testing, caching, and bootstrapping.