I tried to recreate the YouTube algorithm – improvement suggestions?

First started out understanding how to do collaborative filtering and was blow away about how cool yet simple it is.

So I made some users and videos with different preferences (users) and topics, quality and thumbnail quality (videos).

Made a simulation of what they click on and how long they watch and then trained the model by letting it tweak the embeddings.

To support new users and videos I needed to also make a system for determining video quality which I achieved with Thompson sampling.

Got some pretty good results and learned a lot.

Would love some feedback on if there are better techniques to check out?