Not a direct answer to your question, but at least in English there isn’t that much stuff on how TikTok’s recommendation system works internally. This is the best breakdown I have found on TikTok’s recommendation system internals: https://leehanchung.github.io/2020-02-18-Tik-Tok-Algorithm/

There’s a more technical recent paper from bytedance as well: https://arxiv.org/pdf/2007.07203.pdf

And another recent one on bytedance user profile system, this paper gives the deepest understanding of their recommendation system: https://www.cs.princeton.edu/courses/archive/spring21/cos598...

There’s a good breakdown of the recent nytimes article on TikTok’s internals here: https://read.deeplearning.ai/the-batch/issue-122/

If anyone has found anything better let me know.

If you try searching yourself you will want to try switching between the keywords “douyin” “toutiao” “bytedance” and “tiktok.”