You are an expert Software Architect. Analyze the following legacy Python code snippet which handles order processing, payment verification, and inventory management in a single function. 1. Identify violations of SOLID principles. 2. Propose a class structure that separates these concerns. 3. Provide the refactored code using Python 3.10+ type hints. 4. Explain how this new structure facilitates a transition to a microservices architecture. Do not include any markdown headers or code block indicators, just the analysis and code.