Aggregate Interface (IAggregate<T>):?

Short answer: The IAggregate<T> interface defines a method CreateIterator() that returns an iterator instance. Any class that represents a collection should implement this interface to provide an iterator. public interface IAggregate<T>

Example code

{ IIterator<T> CreateIterator(); }

Real-world example (ShopNest)

Use a GoF pattern in ShopNest only when it removes duplication or makes a change safer—explain the problem it solves in the interview.

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.