Databases: SQL vs NoSQL — Part 4: Interview Q&A

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What is this?

This part is a set of mock interviews. For each question you get three things: what they're really asking (the signal behind the words), a model answer (how to actually respond), and the senior line (the one sentence that makes a Staff interviewer lean in).

Keep our records-room office in your back pocket — the ledger, the folders, the corkboard from Parts 1–3 are still the fastest way to make any of this click on a whiteboard. And remember the through-line of this whole topic: databases are chosen by access pattern, relational is the default, and NoSQL has to earn its place.

The one-line idea: in a database interview, the signal isn't which database you name — it's whether you reason from access patterns and trade-offs to get there.