A YouTube playlist sorts by when you added things, which is almost never the order to learn them in. My cofounder got annoyed enough to build something for himself, and we kept going.

  
You paste links: videos, Shorts, a playlist, a channel. They get grouped into tracks by topic, and inside a track each video goes into a tree. Top of the tree is where to start. Deeper nodes assume you've watched what's above them. Every video also gets a summary with clickable timestamps and a chat that quotes the transcript with a timestamp, so you can jump to that spot and check whether it's lying (spoiler: no).

  
How the ordering works: React and TypeScript on the frontend, Supabase behind it (Postgres, Deno edge functions, pgmq queues). For each video we pull out two lists of concepts, what it *teaches* and what it *requires*. Placing a video inside a track means finding the node whose taught concepts cover the new one's required concepts, and hanging it there.

  
Choosing the track in the first place is the messier half, because we're inferring intent from meaning. We take the five closest track names by embedding, plus the tracks of the five most similar videos already in your library, and let the model choose between them. That second signal is there because people don't file things semantically. Someone makes a track called "misc", drops let's plays into it, and every new let's play belongs there even though the name says nothing. Nearest neighbours catch that, but only once a few videos have landed. This approach has its disadvantages, so any ideas on how to improve it are super welcome!

  
Try it at [use-myriad.app](http://use-myriad.app/)

We made a website that figures out what order to watch your saved YouTube videos in