Have you ever been on a web application that felt...janky? slow? glitchy? In today's world, speed and responsiveness are expectations for our customers. A laggy website is the worst user experience. As web developers, this is a huge challenge! Due to the nature of the web, people might be running our software on anything from their phones, to desktop computers, to their fridge! In this talk I will share some techniques that you can use in order to improve performance in your web apps. We will talk about how you can use service workers to keep your app running seamlessly even when there is low network connectivity. Secondly we'll talk about the browser event loop and how you can utilize background threads to run complex code and improve your app's performance. At the end of the session you will have an introductory understanding to two powerful concepts, and the tools to improve the performance of your web apps!