C4 component diagram for CU-22 Calificar Inspeccion—a rating and review submission flow in Mi Peritaje vehicle inspection platform. A buyer or seller accesses a completed inspection report via React frontend, triggering CalificacionController to route requests through CalificacionService business logic, which validates inspection completion and enforces one-submission-per-inspection rules before CalificacionDAO persists ratings (1–5 stars) and reviews (10–500 chars) to PostgreSQL. This architecture demonstrates layered separation of concerns with synchronous REST endpoints, input validation at the service tier, and data access abstraction via SQLAlchemy ORM. Fork and customize this diagram to model your own inspection workflows, rating systems, or multi-step user feedback pipelines on Diagrams.so.