Definition
Event-driven architecture (EDA) is a design pattern in which applications produce, publish and reactJavaScript library from Meta for building component-based user interfaces. to events - discrete messages indicating that something has occurred. An event might be 'supplier switchProcess where an electricity customer changes their power supplier - handled through standardised messages via Elhub. confirmed', 'metering dataData from electricity meters - the foundation for billing, balance settlement and market processes in the power market. received from ElhubNational hub for metering data and market processes in the Norwegian electricity market.' or 'new customer created'. Instead of system A calling system B directly (tight coupling), A publishes an event and B subscribes to it. Event streaming platforms such as KafkaDistributed event streaming platform - widely used for real-time data pipelines and event-driven architectures. and RabbitMQOpen-source message queue for asynchronous and reliable communication between services. are the backbone of EDA. The benefits are substantial: systems can be scaled independently, a failure in one system does not halt others, and the event log serves as a natural audit trail. The drawback is increased complexity in troubleshooting - an error can propagate through many systems via event chains. In the Norwegian energy sector, Elhub communication is in practice event-driven: an E01 message triggers a state change, which in turn triggers the next message step.