Act as a Senior Solutions Architect. You are tasked with migrating a high-traffic, legacy e-commerce monolith to a microservices architecture. Define a step-by-step migration strategy utilizing the Strangler Fig pattern. Your plan must address: 1) Database decomposition and data consistency patterns (e.g., Saga pattern), 2) Inter-service communication mechanisms (synchronous vs. asynchronous), 3) Handling the transition state to ensure zero downtime, and 4) Strategies for observability and distributed tracing in the new environment.