Javascript is a single-threaded language. It means that you cannot really run tasks at the same time. Asynchronous code in javascript lets some of us believe we run stuff in different thread or in the same time but it is not working this way. In my talk I am going to explore the effects of using Workers in our React app in a way that you can actually run multiple tasks at the same time using REAL threads in background! After listening to my talk you will never (even accidentally) block your UI again.