Introduction
Most cloud failures don’t happen at the server level—they happen at the regional level. Day 23 is about designing systems that survive the unthinkable.
Why Multi-Region Matters
Single-region risks:
- Natural disasters
- Power outages
- Network failures
- Regulatory shutdowns
Multi-region architecture ensures business continuity.
AWS Region vs Availability Zone
| Level | Purpose |
| AZ | Fault isolation |
| Region | Disaster isolation |
Multi-Region Architecture Patterns
Active-Passive
- Primary region handles traffic
- Secondary on standby
Active-Active
- Both regions serve traffic
- Complex but resilient
Data Replication Strategies
- S3 Cross-Region Replication
- Database read replicas
- Asynchronous backups
Diagram Description:
Two regions connected via replication paths with DNS-based routing.
Traffic Management
- Route 53 health checks
- Latency-based routing
- Failover routing
Cost vs Resilience Tradeoff
Multi-region systems cost more, but downtime costs more. This cost-awareness mindset is central to how CuriosityTech prepares engineers for real enterprise decisions.
Real-World Use Case
Industries using multi-region:
- Banking
- E-commerce
- Healthcare
- Media streaming
Conclusion
Multi-region architecture is not over-engineering—it is responsible engineering.AWS provides the tools, but design wisdom defines success.
