As Java developers, we know the benefits of type-safety when building apps. The problem? Usually, that type-safety ends when we leave the server. What if it didn't have to be that way? In this presentation, you'll learn how to build a full-stack reactive web app through live code examples. We'll use Spring Boot and Java on the backend and React with TypeScript on the frontend, connecting the two with the new Hilla framework from Vaadin.