This is a project I'm working on at my current workplace, involving making a product recommendation . I'm working in a b2b context with over 30k customers and more than 500k unique sku id.
Light FM paper : https://arxiv.org/pdf/1507.08439.pdf
Beatiful explanation of WARP loss : http://building-babylon.net/2016/03/18/warp-loss-for-implicit-feedback-recommendation/
Light FM python package: https://github.com/lyst/lightfm