Event-Driven Architecture

A software design pattern where components of a system communicate by producing and consuming events rather than calling each other directly, enabling loosely coupled, scalable, and independently deployable services.

Event-driven architecture allows different parts of a system to evolve independently. When a payment is completed, an event triggers the fulfilment system, the notification service, and the analytics system simultaneously without any of them needing to know about each other.

A founder's e-commerce platform emits a "order.completed" event when a purchase is made. Her fulfilment service, email service, and loyalty points service all subscribe to this event and react independently. Adding a new subscriber to the event requires no changes to the checkout code.