Reranking retrieved candidates

Retrieve broadly, then rerank precisely. A reranker reads query and passage together, which is why it beats vector distance on ordering.

What this lesson covers

• Retrieve a wide candidate set, then narrow it
• Score query and passage jointly with a reranker
• Balance the latency cost against the accuracy gain

This lesson sits in Retrieval Quality, part of Retrieval-Augmented Generation from Scratch. It assumes what came before it and leads directly into the next lesson in the module.