Blog/#retrieval

#retrieval

2 posts

• Hybrid search in Python: BM25 + vectors with Reciprocal Rank Fusion, alpha swept 0 to 1

  Tested BM25+RRF on 2,713 FastAPI doc chunks: BM25 beat vectors by 49 MRR points on identifiers; vectors beat BM25 by 24 on paraphrases. alpha=0.8 balanced both.

  27 Sept 2026 · rag · hybrid-search
• RAG chunking, measured: heading-aware chunks doubled hit@1 on the FastAPI docs

  I tested 5 chunking strategies on 151 real docs and 773 queries. Fixed-size chunks crossed section boundaries 59% of the time. Heading-aware chunks never did.

  27 Sept 2026 · rag · chunking