RAG Deep Dive: Principles, Optimization & Production Implementation
This comprehensive guide explains RAG from first principles through production deployment, covering offline indexing (loading, chunking, embedding, vector storage), online query pipeline (retrieval, reranking, prompt assembly), hybrid search with BM25 and dense vectors, RRF fusion, cross-encoder reranking, evaluation metrics (recall@k, MRR, nDCG), query rewriting, metadata filtering, contextual retrieval, Agentic RAG, and a real-world case study building a style-matching writing assistant with 197 articles.
