TL;DR
Auth platform maintains 99.999% SLA during October 2025 AWS us-east-1 DynamoDB outage by implementing multi-region failover, strict dependency reliability constraints, and DNS-based dynamic routing.
Key Points
- October 20, 2025: us-east-1 DynamoDB DNS failure took down Disney+, Reddit, Lyft, NYT; Authress remained operational
- Five-nines SLA allows only 5m 15s downtime annually; requires third-party dependencies to meet minimum 99.7% reliability
- Architecture uses six primary regions with backup failover regions; DNS dynamic routing automatically switches on regional failures
- Retry handler reliability must exceed service SLA (5.5+ nines) to avoid compounding failures across retry attempts
Why It Matters
This deep-dive reveals the mathematical and architectural constraints required to build genuinely reliable infrastructure in cloud environments where underlying services fail regularly. For developers building critical services, it demonstrates that SLA guarantees require active multi-region strategies and strict dependency vetting—not just redundancy.
Source: authress.io