cool project, i was curious which algorithms are used for recommendations/ranking, couldn't find it in the docs, so had to go through the code, may be add a section on algorithms and models?

it seems that one algo used is "Bayesian Personal Ranking" based on a paper from 2012 https://arxiv.org/pdf/1205.2618.pdf, here is a related blog post https://towardsdatascience.com/recommender-system-using-baye...

another one is Weighted Regularized Matrix Factorization/ALS (by the Netflix Prize winner team): http://yifanhu.net/PUB/cf.pdf , also see https://www.ethanrosenthal.com/2016/10/19/implicit-mf-part-1...