Junior EF Core interviews ask "what is a DbContext." Senior interviews ask why your dashboard fires 200 queries to render one page , what happens when two users save the same row at once , and why calling Migrate() on startup took production down during a rolling deploy .

EF Core makes the easy 80% trivial and hides the hard 20% — change tracking, query translation, concurrency, and schema evolution — right where production breaks. Seniority is knowing what SQL your LINQ actually becomes and what EF is doing on your behalf.

This is 30 questions across change tracking & the DbContext, querying & performance, concurrency & transactions, and migrations & production . Each has a short answer, a deep dive into the mechanism with code, and the senior signal the interviewer is listening for.…