What are join tables / linking tables?

Short answer: How to represent them in EF Core? A join table maps a many-to-many relationship. In EF Core: ✅ Auto-created (EF Core 5+): If you define many-to-many with ICollection<T>, EF creates the join table. 🛠 Manual (custom join entity): public class StudentCourse

Example code

{
public int StudentId { get; set; }
public Student Student { get; set; }
public int CourseId { get; set; }
public Course Course { get; set; }
} And configure with Fluent API.

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.