In the quest to build microservice systems that are elastic and resilient, Event-Driven Architecture (EDA) comes with the highest acclaims. But what does it actually mean? At what point is a system really event-driven, and what seperates it from one that's merely based on asynchronous messaging? How does event-driven architecture impact the service boundaries and design? And how to deal with about complex workflows and sagas? The presentation provides an overview of the principles and central concepts, show-casing some real life stories "from the trenches". It'll serve as a basis for an informed discussion about the potential and challenges of event-driven microservices.