This talk is about flow, a static type-checker for JavaScript which is developed and maintained by Facebook. We have been using flow extensively at QuizUp for half a year now and it's been a great success in a big JS codebase. In this talk I will answer the following questions:
What is it?
Why use it?
What can it do?
What can't it do?
Lastly I will go over lessons learned and our experience with using flow.