System designHardsd-g662

Subject Database replicationLevel Senior–Staff~50 minCommon in Databases & SQL · Distributed systems interviewsIndustries Technology, Software development

Question

Design a multi-region replicated database for a global SaaS app with users in NA, EU, and APAC, serving 150k reads/sec and 30k writes/sec. Reads should be served locally (sub-10ms in-region) and writes must survive the loss of an entire region with zero data loss. EU user data must physically reside in the EU. What replication topology and consistency model do you pick, and how do you handle a region failover?

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.