
LLM Recommendation Systems: Retrieval, Ranking, RAG, and Evaluation
Recommendation systems create a tempting illusion: the newer the model, the more advanced the system. Anyone who has operated one knows that the model is only the part above water. Below it sit exposure bias, latency budgets, feature freshness, inventory constraints, exploration risk, and counterfactual evaluation. Large language models add a useful semantic layer, but they do not make those older problems disappear. They also introduce new ones: higher cost, variable output, and explanations that can sound persuasive without reflecting the reasons an item was ranked. ...









