Each video is node. Figure out where to add edges to existing content, graph theory some shit and tune for similar content maximizing viewing time of short video clips. No ML necessary. Of course, given the magic ML sometimes seems to be, they could certainly be using it but the inputs and outputs are remarkably simple if you get the data structures right. To be clear, I'm not saying it's easy, just that ML's not necessary.
You jest, but at this point YouTube’s recommendation system sees even less complicated than this. Just random videos from years ago will one day become blessed by the algorithm and receive millions of views.
YTs algorithm now just seems to amplify very, very small fluctuations in view counts. 3 people just happened to watch the same video at the same time? It must be trending! Shove it in front of everyone. It’s like Google has used all of machine learning to recreate taking a derivative.
