Do You Actually Need Multi-Region?
Most teams conflate "high availability" with "multi-region." For many B2B SaaS products, multi-AZ within one region plus solid backups meets 99.9% SLAs at a fraction of the cost.
Multi-region makes sense when latency to global users is business-critical, regulatory data residency requires it, or downtime costs exceed six figures per hour.
Patterns That Work
Active-passive, Primary region serves traffic; secondary warms on failover. Simplest to operate.
Active-active read, Writes go to one region; reads replicated globally. Good for content-heavy apps.
Cell-based architecture, Tenant shards pinned to regions. Best for enterprise SaaS with data residency contracts.
Cost Traps
- Cross-region data transfer fees on every request
- Unbounded database replication lag causing split-brain writes
- Running full duplicate environments "just in case" without failover drills
Conclusion
Design for the SLA your customers pay for, not the architecture diagram that looks impressive in a pitch deck. Talk to our cloud team about a right-sized plan.
