Guides

Reference & Learning

Living documents covering fundamental concepts, tools, and techniques. Unlike articles, these are regularly updated as understanding evolves.

Reciprocal Rank Fusion for Hybrid Search

Updated FEB 14, 2026

A comprehensive guide to using Reciprocal Rank Fusion (RRF) to combine BM25 and semantic search results for production RAG systems.

BM25 Search in LLM Systems

Updated DEC 22, 2025

A comprehensive, interactive guide to understanding the BM25 ranking algorithm for AI engineers building RAG systems and search applications.

Stay in the loop

Get notified when I publish new articles on RAG, search, and AI systems.

 

Cole Hoffer·TwitterLinkedIn