Have you ever designed logical data models (ER diagrams)?

Yes, I have experience designing logical data models using ER diagrams.

ER diagrams help visualize entities, their attributes, and relationships between them, which facilitates understanding the data structure and database requirements.

For example, when designing a order management system, entities such as "Customer", "Order", "Product" were created with corresponding relationships (one customer can have many orders, an order contains multiple products). This allowed identifying key fields and constraints, as well as preparing the foundation for physical database design.