Data/ML/AI
Recommendation System
Also written as Recommender System, Collaborative Filtering, Personalization Engine
A system that predicts what a particular user is likely to want next, from what that user has done before and what similar users did.
Think of it like
A bookseller who remembers what you bought, and what people with your taste bought after it.
Junior or senior?
Common at consumer scale.
Senior sounds like
Talks about the cold start for brand-new users and items, and about measuring lift rather than offline accuracy.
Ask them
“What did you show a brand-new user with no history, and how did you measure whether recommendations helped?”