Example 1 EXECUTIVE SUMMARY Global SaaS collaboration platform supporting messaging, video calls, file sharing, and search. SYSTEM CLASSIFICATION Primary: SaaS Platform Secondary: Real-Time System Complexity: High REQUIREMENT ANALYSIS Functional: - Messaging - Video calls - File sharing Non-Functional: - Low latency - High availability HIGH-LEVEL ARCHITECTURE Frontend: React Backend: Node.js Database: PostgreSQL Cache: Redis Queue: Kafka ARCHITECTURE DECISIONS Decision: Kafka Reason: Real-time event processing Trade-Off: Higher operational complexity TECHNOLOGY SELECTIONS Application: Node.js Database: PostgreSQL Cache: Redis DATABASE ANALYSIS Recommended: PostgreSQL Reason: Transactional consistency TRADE-OFF ANALYSIS Option A: PostgreSQL Pros: Consistency Cons: Scaling complexity Option B: MongoDB Pros: Flexibility Cons: Weaker transactions Recommended: PostgreSQL SCALABILITY PLAN MVP → Single Region Growth → Read Replicas Scale → Regional Clusters Global → Active-Active CAPACITY PLAN Peak Requests: 50k/sec Storage Growth: 5TB/month PERFORMANCE ANALYSIS Target Latency: <150ms Caching: Redis RELIABILITY ENGINEERING Availability: 99.95% RTO: 15 Minutes RPO: 5 Minutes GLOBAL DISTRIBUTION STRATEGY Recommended: Active-Passive Multi-Region SECURITY ARCHITECTURE OAuth2 TLS AES-256 COMPLIANCE REVIEW GDPR Applicable OBSERVABILITY STRATEGY Prometheus Grafana OpenTelemetry COST OPTIMIZATION Major Cost Driver: Video infrastructure BUSINESS IMPACT ANALYSIS Revenue Impact: High Strategic Importance: High BOTTLENECK ANALYSIS Risk: Search indexing FAILURE ANALYSIS Database Failure → Automated Failover ARCHITECTURE EVOLUTION ROADMAP Monolith → Modular Services → Microservices DEVOPS STRATEGY GitHub Actions Blue-Green Deployments TEAM SCALING PLAN Platform Team Product Team Infrastructure Team ANTI-PATTERN REVIEW Risk: Premature Microservices ARCHITECTURE REVIEW BOARD Recommendation: Recommended With Modifications ARCHITECTURE SCORECARD Scalability: 9/10 Reliability: 9/10 Security: 8/10 FINAL RECOMMENDATION Proceed with phased rollout. VALIDATION SUMMARY ✓ Architecture designed ✓ Security reviewed ✓ Reliability reviewed ✓ Bottlenecks identified ✓ Review board completed