Tolerating full cloud outages with Monzo Stand-in
Summary
Monzo explains how it built a separate Stand-in backup banking infrastructure on Google Cloud Platform to take over during major outages, operating independently from the primary AWS platform. The article covers cross-cloud architecture, data syncing with eventual consistency, cost considerations, and the controlled enablement of Stand-in during incidents, including a real outage in 2024. This provides actionable insights into resilient, cost-aware DR strategies for fintech-scale services.