An event broker is middleware software, appliance or SaaS used to transmit events between event producers and consumers in a publish-subscribe pattern. According to Gartner, event brokers “are middleware products that are used to facilitate, mediate and enrich the interactions of sources and handlers in event-driven computing.” “Event-driven architectures (EDA) is inherently intermediated. Therefore, the intermediating role of event brokering is a definitional part of EDA. All implementations of event-driven applications must use some technology in the role of an event broker.”* https://solace.com/what-is-an-event-broker/