Engineering Blog

Ideas from the ZettaBrain Team

Deep dives into private AI, multi-tenant RAG, and building production-grade document intelligence — on-prem.

RAG Multi-Tenant BM25

Per-Tenant BM25 in Hybrid RAG: How We Fixed Cross-Boundary Document Leakage

A shared BM25 index poisons IDF scores across tenant boundaries even when your vector store is correctly isolated. Here's how we caught it and fixed it with per-team BM25 indices.

Olajide Shobowale  ·  May 2026 Read →