xai-org/x-algorithm ? reverse-engineered prompt

I want to build a recommendation feed, basically a clone of the X "For You" algorithm. The main goal is to create a personalized feed for a user by mixing posts from people they follow with new posts discovered from a wider network.

The core of the system should be a smart ranking model, like the Grok-based transformer mentioned in the XAI release. This model should analyze a user's engagement history—their likes, replies, reposts, etc.—to predict how likely they are to interact with new posts. The final feed should be ranked based on these predictions.

Please also include logic to handle the whole pipeline: fetch the candidate posts from both sources, filter out things like duplicates or content from blocked users, and ensure there's some author diversity so the feed doesn't get repetitive. It's a high-performance system, so let's build the backend services in Rust.