This is the kind of question where you think you know it until you're drawing boxes on a whiteboard and someone asks you how you handle metadata at scale.
Start by clarifying requirements and constraints, then design a scalable, durable object storage system with a focus on data partitioning, replication, and consistency. Discuss trade-offs between consistency, availability, and durability, and explain how components like metadata management, storage nodes, and access APIs interact.
Pro tip: Emphasize durability and scalability from the start, as Apple values reliability and seamless user experience. Mention how you would handle failures gracefully and ensure data integrity at scale.
Ask about scale (e.g., petabytes, billions of objects), durability, availability, consistency, and access patterns. Confirm whether it's for internal use or public cloud.
Outline core components: clients, API gateway, metadata service, storage nodes, and replication. Sketch data flow for PUT/GET operations.
Explain how objects are stored (e.g., as blobs with unique IDs), metadata schema, and partitioning strategy (e.g., consistent hashing) for scalability.
Describe replication (e.g., cross-region, erasure coding) and failure handling. Discuss trade-offs between replication factor, cost, and durability.
Address consistency models (e.g., eventual vs. strong), caching, and optimizations for high throughput and low latency.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.