[eterevsky]

I work on Google Assistant Suggestions and I don't think it's very practical to open-source an algorithm like that including the models and the underlying data. Both of them can live in separate services and be frequently updated.

I am assuming that open sourcing the code aims to increase transparency about the business logic of the ranking decisions. At the same time you don't want spammers to be able to easily run experiments against a cloned version of your system.