Before API integration, you need to confirm several things: First, do the "customer," "product," and "order" field definitions in both systems align? For example, customer ID format and product SKU naming conventions. Second, is this one-way synchronization (e.g., pushing POs to ERP after confirmation) or two-way synchronization (e.g., ERP inventory data also flows back)? Third, what is the sync trigger mechanism—real-time, scheduled batch, or manual? These decisions will affect the complexity and maintenance cost of the integration. We recommend conducting sandbox testing with a small amount of real data before going live to confirm that field mappings are correct, avoiding difficult data cleanup later.