What is optimistic concurrency?

Short answer: How to implement it? Assumes conflicts are rare; detects conflicts when saving. Uses concurrency tokens (e.g., timestamp or row version) to detect if data was changed by another process. EF Core throws DbUpdateConcurrencyException if a conflict occurs.

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.