Filmed at https://2018.dotjs.io on November 9th in Paris. More talks on https://dotconferences.com/talks Sometimes, undefined is not a function. As mortal programmers, we ship bugs to production everyday. Bugs slow us down, frustrate our users, and cause us to have crises of confidence. Don't go alone–type systems in technologies such as TypeScript, Flow, and GraphQL can improve your confidence and help you ship less bugs. Lauren dives into the practical benefits you'll get from embracing types. You'll walk away with a better understanding of why type systems help you write better programs, and some functional programming tips you can use today.