Resilience Architecture

Multi-AZ deployment handles many practical startup failure scenarios without multi-region complexity. The cited AWS outage was attributed to internal high-availability automation rather than hardware or network failure. Automation, replication, and configuration machinery create unexpected failure paths. High-availability systems can create outages through their own complexity. Multi-region systems add expense, operational burden, replication complexity, and consistency tradeoffs. Global strong consistency can severely harm performance and scaling.