Depending on the size of the company (Revenue), and where / how the recommender system sits within the customer experience; Logistic regression could be fine. A

Depending on the size of the company (Revenue), and where / how the recommender system sits within the customer experience; Logistic regression could be fine. An even better baseline if discovery isn't so important for a good CX is to go with most popular and or a vendor. Building these systems used to be about getting lots of different things to work together which eats up a lot of time, and capacity (Product, UX, Eng) and it may not get the appropriate return.