Deduplicating backup system
Design a deduplicating backup-and-restore system for an enterprise fleet: thousands of machines back up nightly, most data is unchanged or duplicated across machines (OS files, shared assets), and you need space-efficient storage, fast incremental backups, and reliable point-in-time restore of any machine. How do you deduplicate, store, and restore — and what breaks at scale?
What a strong answer looks like
Clarify scale and constraints first. Propose a clean component breakdown, then go deep on the hard parts (data model, bottlenecks, consistency, failure modes) and name the trade-offs you are making.
Clarify5:00 left
Estimate5:00 planned
Design15:00 planned
Deep dive12:00 planned
Failure8:00 planned
Which questions mattered is sealed until you submit. Telling you now would just be handing over the edge cases.
Run or narrate your approach, then ask the coach.