### 1. Business Impact Analysis (BIA) & System Tiering Matrix | Criticality Tier | System Component | Maximum Tolerable Downtime (MTD) | Target RPO | Target RTO | Financial & Operational Impact | | :--- | :--- | :--- | :--- | :--- | :--- | | **Tier 0 (Mission-Critical)** | RDS PostgreSQL Transaction Ledger | 2 Hours | 15 Minutes | 45 Minutes | Transaction halt; direct revenue loss; regulatory reporting breach. | | **Tier 1 (Core Operations)** | EKS Ingestion API & Stripe Webhooks | 4 Hours | 0 Minutes (Stateless) | 1 Hour | Inbound webhook drop; payment queue buildup; merchant SLA penalties. | | **Tier 2 (Internal Systems)** | Redis Caching & DynamoDB Session Store | 12 Hours | 1 Hour | 3 Hours | Elevated latency; session invalidation; users forced to re-authenticate. | | **Tier 3 (Supporting Services)** | BI Data Warehousing & Metabase Analytics | 48 Hours | 24 Hours | 24 Hours | Non-critical reporting delay; zero immediate customer impact. | --- ### 2. High-Availability Failover & Technical Recovery Runbook * **Phase 1: Outage Declaration & DNS Diversion (T+0 to T+15 min)** Confirm primary region total failure via three independent health check nodes. Incident Commander authorizes regional cutover. Update AWS Route 53 latency routing policies to direct incoming traffic to secondary ingress endpoints in US-West-2. * **Phase 2: Database Restoration & Promotion (T+15 to T+35 min)** Promote cross-region RDS read replica in US-West-2 to standalone primary writer mode. Replay latest point-in-time WAL logs from immutable S3 replicate bucket to capture transactions up to the 15-minute RPO threshold. * **Phase 3: EKS Cluster Elastic Auto-Scaling (T+35 to T+45 min)** Scale standby EKS deployment worker nodes from minimum baseline to full production capacity using Terraform infrastructure automation scripts. Verify environment secrets and API signing keys via AWS Secrets Manager replication. * **Phase 4: Post-Cutover Sanity Testing (T+45 to T+60 min)** Execute synthetic payment test transactions against sandbox processors. Validate inbound webhook replay queues and restore merchant traffic. --- ### 3. Crisis Management Escalation Tree & Communication Protocol * **Command Structure:** Incident Commander (VP of Engineering) holds final cutover authority. Technical Lead (Lead DevOps) executes technical runbooks. Communications Lead (Compliance Officer) manages external updates. * **Internal Notification Cadence:** P1 incident declared via automated PagerDuty escalation; war room bridge established within 5 minutes. Technical status updates broadcast to internal engineering Slack channels every 20 minutes. * **External Customer Communications:** Merchant status page updated within 15 minutes of outage declaration. Dedicated email notification dispatched to Tier-1 enterprise partners within 45 minutes. * **Regulatory Compliance Disclosures:** If transaction data loss exceeds 15 minutes, notify PCI forensic investigator and state banking regulators within the mandatory statutory reporting window. --- ### 4. Annual Tabletop Simulation Scenario & Testing Audit Checklist * **Exercise Scenario:** Simultaneous AWS US-East-1 data center degradation coupled with an automated administrative credential compromise attempting to delete database snapshots. * **Simulated Injected Variables:** Primary Route 53 console unreachable; secondary on-call DevOps engineer unresponsive; S3 Object Lock successfully defending backup data integrity. * **Audit Evaluation Criteria:** Verification that secondary replica promotion occurs within 35 minutes; confirmation that no engineer possesses credentials capable of bypassing immutable storage lock; validation of clear external messaging delivered without technical jargon. * **Post-Mortem Action Items:** Complete root-cause analysis within 72 hours; document automated failover script errors; update infrastructure Terraform configurations.