System designEasysd-g564

Subject Key value storeLevel Entry–Mid~25 minCommon in Distributed systems interviewsIndustries Software development, Technology

Question

Design a per-user settings/preferences store for a small app (theme, notification preferences, default view, and a handful of other toggles that may grow over time). Settings are read when a user loads the app and written occasionally when they change a preference. Describe how you model settings that can evolve without a schema migration every time you add one.

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.

Learn the concepts

Narrate your design

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Run or narrate your approach, then ask the coach.