Serializable: Prevents dirty, non-repeatable, and phantom reads. This is the most?

Short answer: restrictive but guarantees the highest level of consistency. You set the isolation level using the Transaction object: SqlTransaction transaction = connection.BeginTransaction(IsolationLevel.Serializable);

Real-world example (ShopNest)

ShopNest’s reporting job still uses ADO.NET for a heavy SQL query where raw performance and stored procedures matter more than EF convenience.

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.