System designHardsd-g715

Subject DurabilityLevel Senior–Staff~45 minCommon in Databases & SQL · Storage & CDN · Distributed systems interviewsIndustries Technology

Question

Design a write-ahead-log shipping and replication system that keeps a hot standby (and cross-region replicas) in sync with a primary database for high durability and fast failover. The primary commits thousands of transactions/sec; you must bound data loss on primary failure (a target RPO) and bound failover time (RTO), and support point-in-time recovery. How do you ship the log, apply it on replicas, and fail over safely?

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.