The Moon framing isn't just flavor, it actually breaks a lot of your default assumptions.
Start by clarifying requirements and constraints (e.g., data size, access patterns, consistency needs, link characteristics) to scope the problem. Then propose a design that prioritizes local storage and operations on the Moon, with asynchronous replication to Earth, and discuss trade-offs between availability, durability, and consistency. Finally, address failure modes and how the system adapts to intermittent connectivity.
Pro tip: Emphasize that the system must be designed for partition tolerance and offline-first operation, and discuss how you would handle conflict resolution when the link is restored. This shows you understand the realities of distributed systems in extreme environments.
Ask questions to understand data volume, read/write patterns, latency tolerance, consistency requirements, and the nature of the Earth link (bandwidth, frequency, duration).
Propose a layered design: local blob storage on the Moon (e.g., distributed file system or object store), a metadata service, and a replication/sync service to Earth.
Decide on blob organization (e.g., immutable blobs, versioning), metadata indexing, and storage hardware considerations (limited capacity, radiation hardening).
Design asynchronous replication to Earth with eventual consistency, and discuss conflict resolution strategies (e.g., last-write-wins, vector clocks, CRDTs).
Address how the system handles link outages, storage failures, and degraded modes; include monitoring, alerting, and graceful degradation.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.