Think you know everything about McDonald's? What about its event-driven architecture?

McDonald's standardizes events using the following components:

• Event Registry: An event registry to define a standardized schema.
• Custom SDKs: Custom software development kits (SDKs) to process events and handle errors.
• Event Gateway: An event gateway that performs identity authentication and authorization.
• Utilities and Tools: Utilities and tools to fix events, keep the cluster healthy, and perform administrative tasks.

To scale event processing, McDonald uses a regional architecture that provides global availability based on AWS. Within a region, producers shard events by domains, and each domain is processed by an MSK cluster. The cluster auto-scales based on MSK metrics (e.g., CPU usage), and the auto-scale workflow is based on step-functions and re-assignment tasks.

Reference: Behind the scenes: McDonald’s event-driven architecture