How to deal with concurrency exceptions?

Short answer: Catch DbUpdateConcurrencyException. Reload conflicting entity from database or merge changes. Retry operation or notify the user of conflict. Implement custom conflict resolution logic as needed. Testing, Deployment, Tools

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.