Web-based applications have come a long way since we used to serve static HTML content from servers. Nowadays, applications are much more complex and use multiple frameworks, data centers, and technologies. In this article, we’ll discuss some of the problems driving innovation in modern web development. Then we’ll dive into the basics of event-driven architecture (EDA), which tries to address these problems by thinking about back-end architecture in a novel way. We focus on the challenges that always-on, multi-user, asynchronous applications face today, such as availability, scalability, single source of truth, and synchronicity. The article sheds light on the techniques and practices to overcome these challenges by using event-driven architecture (EDA).