Omnichannel retail architecture integrating on-premises POS systems with cloud-based ecommerce through secure VPN, API Gateway, and event-driven message brokers. Data flows from the POS System (source of truth) via local POS Connector through VPN Gateway to cloud services: Order Service, Catalog Sync Service, and Status Update Queue orchestrate inventory, orders, and pricing across web and mobile channels. Redis caching and CDN/WAF protect the Ecommerce App Service while Message Broker and Durable Order Queue ensure reliable order processing with dead-letter handling and retry logic. This architecture solves the critical retail challenge of maintaining real-time inventory synchronization and order visibility across store and online channels while protecting sensitive POS data behind firewalls and VPN encryption. Fork this diagram on Diagrams.so to customize subnets, add payment processors, or integrate additional branch locations. Consider adding API rate limiting and circuit breakers at the API Gateway for handling traffic spikes during peak retail seasons.