I have extensively worked on both implicit and explicit kind of recommender systems .
past project :
1) Made a recommender system based on user interaction using Collabrative filtering and SVD for a retail company "Bigbazaar".
2) I have also built an implicit recommender for yandex using MF for recommending the items to a customer in international data olympiad , Moscow.
I have also used "python spotlight for recommendation" in my past work which used deep learning for recommendation engines.