Enterprise application architecture, complex system diagram, layers, tiers, hexagonal architecture, microservices, event-driven design, domain-driven design, command query separation, API gateway, service discovery, circuit breaker, load balancer, distributed transaction, message queue, event sourcing, CQRS, scalable, flexible, modular, maintainable, technology-agnostic, cloud-native, containerized, orchestrated, DevOps, monitoring dashboard, logging aggregator, alerting system, analytics platform, data visualization, real-time processing, fault-tolerant, highly available, security-focused, compliance-ready, standards-based.