Design a highly scalable e-commerce system using Java, Spring Boot, Microservices, Kafka, AWS, caching, and a relational database -- how would you handle failures, traffic spikes, and data consistency?

Tests whether you can tie the pieces together coherently -- Kafka to decouple order placement from fulfillment and absorb spikes, caching for read-heavy catalog paths, and sagas/outbox for cross-service consistency -- rather than listing each technology in isolation.