How to use Fluent API features (HasOne, HasMany, WithOne, WithMany)?

Short answer: Configure relationships explicitly. HasOne / WithMany to define navigation properties and cardinality. Offers fine control beyond Data Annotations.

Real-world example (ShopNest)

ShopNest’s order service uses EF Core to save an Order and its line items in one SaveChangesAsync() call inside a transaction.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.