# Event-Driven Architecture Event-Driven Architecture (EDA) is a software design pattern in which the flow of the program is determined by events -- significant changes in state or occurrences that the system detects and responds to. Components communicate by producing and consuming events rather than through direct request-response calls. In an event-driven system, event producers emit events to a message broker or event bus (such as Apache Kafka, AWS EventBridge, or RabbitMQ), and event consumers subscribe to and process events asynchronously. This decoupling allows components to evolve independently and improves system resilience, since a failure in one consumer does not block the producer. Event-driven patterns complement API gateway architectures. An API gateway can accept synchronous HTTP requests from clients and publish them as events for asynchronous processing by backend services. This hybrid approach provides a clean external API interface while leveraging the scalability and loose coupling of event-driven processing internally. Serverless functions are natural event consumers, triggered by messages on queues or topics. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.serverlessapigateway.com/glossary/e/event-driven-architecture.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.