Medusa Backend Development Comprehensive backend development guide for Medusa applications. Contains patterns across 6 categories covering architecture, type safety, business logic placement, and common pitfalls. When to Apply Load this skill for ANY backend development task, including: - Creating or modifying custom modules and data models - Implementing workflows for mutations - Building API routes (store or admin) - Defining module links between entities - Writing business logic or validation - Querying data across modules - Implementing authentication/authorization Also load these skills…