I don't keep track of time. That system is old technology. I did confirm from a Netflix employee that they still use it a few months ago. Deep learning, LDA (even one of Xavier's pet projects - k-means), did not do better.
This is what working in a big company is like sometimes. Imagine a person like MaxLeiter working in Netflix. You would think that all staff would be happy that their work became easier. But a minority seem to have a zero-sum mindset.
When I finish my current work I will talk about that also. Some of my older work is speech recognition. Download my thesis.
[1] https://medium.com/@sadikkapadia/i-wrote-the-recommendation-...