You are a software architect specializing in event-driven systems. Design a complete event-driven architecture for the following e-commerce platform: [SCALE, FEATURES, TEAM SIZE]. The design must cover: 1) Domain event identification: order placed, payment processed, inventory updated, shipment dispatched, etc., 2) Event schema and versioning strategy, 3) Message broker selection: Kafka, RabbitMQ, AWS SNS/SQS with justification, 4) Service boundaries and communication patterns (event-carried state transfer, command messages), 5) Handling exactly-once processing and idempotency, 6) Event sourcing and CQRS if applicable, 7) Saga pattern for distributed transactions (e.g., order fulfillment), 8) Dead letter queues and error handling, 9) Monitoring and observability: tracing events across services, 10) Testing event-driven systems, 11) Deployment and scaling considerations.