A global app needs low-latency reads for users on three continents with writes consolidated to one Region — no multi-Region write conflict handling allowed. Which design fits?
A.Active/active writers in all three Regions
Multi-writer invites exactly the conflict problem that's disallowed.
B.Single writer Region + read replicas/edge caching + Route 53 latency routing
Correct. Single-writer + distributed reads meets all constraints.
C.Three independent stacks with periodic data sync
Async sync creates divergence and operational complexity.
D.One Region, larger instances for all users
Instance size doesn't solve geographic latency.
Why this answer
Consolidating writes to one Region avoids conflict resolution entirely; cross-Region read replicas (or CloudFront-cached reads) serve reads locally; latency-based routing sends users to the best endpoint.
Correct answer: B · Last reviewed 2026-10-26
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