Rec System Infra Basics Infra Basics:

  1. What do users want?
  2. How can we scale?

We might have blackbox. Where for a user and video we can get a score.

Pre- calculate scores? No, still takes too long.

Candidate Generation -> Ranking -> Re-Ranking

Simplest system -> Show most popular vids

Candidate Generation

  • Channels I’m subscribed to
  • Top videos on the platform
  • Videos Similar to the one I liked (use embeddings)
  • Videos watched by users like me (use embeddings
  • Have vector tables for these embeddings Re-Ranking