Week 16 comprehensive integration: All 13 weeks + 15 weeks of separate pillars must now act as one coherent design.
The fundamental truth: No pillar lives alone. Choosing Aurora Global (Reliability RPO<1s) costs 2x vs RDS Multi-AZ (Reliability RPO 0). Adding Multi-Region (Reliability + Disaster Recovery) increases latency (Performance -) and cost (Cost -). Encryption (Security +) reduces throughput (Performance -). Logging everything (Security + Compliance +) explodes storage costs (Cost -).
Pro architect sees the trade-off matrix and makes prioritized choices based on business context, not equal pillar weight.