Wu Shixiong's Large Model Academy

Mar 21, 2026 · Artificial Intelligence

Step‑by‑Step Guide to Implementing a Hybrid Retrieval Function with RRF Fusion

This article breaks down the end‑to‑end retrieval function used in a RAG system, detailing each of the five stages—from request construction, hybrid vector + BM25 search, RRF fusion, cross‑encoder reranking, to threshold filtering—and provides concrete Python code, parameter choices, and performance insights.