distributed key value stores

The Dynamo question. Interviewers want three decisions made cleanly: how you partition keys so adding nodes does not reshuffle everything, how you replicate for durability, and where you land on the CAP spectrum. Here is how to reason about all three with concrete quorum math.

A deceptively rich warm-up. The interesting decisions are how you generate short, collision-free, unguessable keys at scale, and how a read-heavy 100:1 workload shapes the storage and caching. Here is the clean design with capacity math.