Analyze the following description of a monolithic legacy codebase [describe monolith constraints, e.g., single database, tight coupling]. Propose a comprehensive strategy to refactor this into a microservices architecture. Your response must include: 1) Identification of logical bounded contexts for service separation, 2) A data migration plan that handles data consistency during the transition, 3) A strategy for implementing inter-service communication (sync vs async), and 4) Potential pitfalls regarding distributed transactions and how to avoid them.