When a Cloud Region Hiccups, Your Roadmap Shouldn’t
Summary
If one zone or region goes down and revenue stops, that’s a design problem…not “bad luck.” Build for failure up front: spread the load, set simple SLOs (speed and uptime targets), and practice failover like a fire drill. Don’t ship slideware; ship resilience.
Why this matters
Modern apps depend on shared services…DNS, load balancers, queues, data stores. When any one of those stalls, the impact spreads fast. The fix isn’t more slides; it’s architecture and drills that work under pressure.
What “good” looks like
Multi-AZ baseline; multi-region for Tier-1 paths. If your checkout, login, or API gateway can’t run in another region today, that’s the first gap to close.
Clear SLOs. Pick two numbers: response time and availability. Use an error budget to decide when to slow feature work and fix reliability debt.
One-page runbook. Owners, steps, and contact paths. No hunting for wikis while customers wait.
Real drills. Time your failover. If you’ve never rehearsed it, assume it won’t work.
A 30-minute failover drill (start here)
Pick one critical service (e.g., API gateway).
Flip traffic to your secondary zone/region using your current method (DNS, LB, or feature flag).
Watch three signals: p95 latency (the slow end of normal), error rate, and user impact.
Roll back and capture time-to-recover, who did what, and where you got stuck.
Fix one blocker within 48 hours and schedule the next drill.
What to measure (keep it simple)
Time to failover: minutes, not hours.
p95 latency & error rate: during and after the switch.
Blast radius: which users or features felt it?
Human path: did the on-call know exactly what to do?
When to diversify providers
Stay single cloud unless your Tier-1 path keeps getting hit or compliance demands it. If you do mix, keep it narrow: one or two workloads only, with a clear SLO and cost model.
The operator’s take
Outages will happen. The teams that win treat resilience like a product feature: they scope it, ship it, and measure it. Make failover boring…and repeatable.