Blue-Green Deployment:?

Short answer: Maintain two identical environments (Blue and Green). Traffic is routed to one (e.g., Blue) while the new version is deployed to the other (Green). After testing, switch the traffic to the Green environment.

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.