The document discusses adding real-time capabilities to applications. It begins with an introduction to real-time needs in applications and challenges with existing web technologies. It then covers the history and evolution of the web from documents to more dynamic applications. Various real-time architectures and technologies are presented, including websockets and pub/sub messaging. Examples of using real-time for chat, notifications, and live updates are provided. It emphasizes separating real-time concerns from application logic and stresses the importance of testing real-time capabilities under different load scenarios.