What design pattern helps in implementing Undo/Redo functionality?

Short answer: The Command Pattern encapsulates requests as objects, allowing operations to be stored, undone, or redone by maintaining command history.

Real-world example (ShopNest)

Patterns in ShopNest should solve a real pain (swappable payments, test seams)—not be added for decoration.

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.