Act as a Senior Solutions Architect. Design a scalable microservices architecture for a global e-commerce platform handling 100k concurrent users. Your design must include service decomposition (e.g., Inventory, Orders, Users), API Gateway selection, inter-service communication patterns (synchronous vs asynchronous), database strategy (per-service polyglot persistence), caching layers (Redis), and a resilience pattern (Circuit Breaker, Retry). Explain the trade-offs between consistency and availability in your design.