How recommendation engines work

A simple guide to how Google, Facebook, Amazon and other platforms make accurate product recommendations for users.

You go to the local supermarket, and you buy a pack of noodles, a crate of eggs, some spicy Cameroon pepper, and 2 kilos of frozen chicken. Then you proceed to check out your purchases. From everything you bought, it can be safely assumed that you’re trying to beat the Indomie adverts at their own game. But there’s one key thing missing, so the cashier says. ‘Sir/Madam, won’t you buy some fresh groundnut oil? We have several brands in stock’. The cashier goes ahead to list some of them and maybe their prices. You may or may not buy one eventually.

Nevertheless, the cashier has made a fairly accurate recommendation of something you ought to be interested in based on your purchases. In the simplest of terms, this is what a recommendation engine does.

Last updated: January 30, 2025