We Shipped a RAG Chatbot to 500 Enterprise Tenants. Here's What Actually Broke First.

Our first enterprise tenant onboarded on a Monday. By Wednesday, 30% of their documents had been silently indexed as empty strings. No error. No exception. The chatbot just said "I don't have enough information", confidently, every time. That was Failure #1. There were four more. Here's the honest account of shipping a multi-tenant RAG chatbot to 500+ enterprise clients — what broke, in what order, and what we should have caught earlier. The System We Built Before the failures, the context. We built a RAG chatbot for enterprise warehouse management. Each tenant had their own isolated knowledge base — SOPs, compliance documents, operational guides. Users queried only their tenant's data. Scale target: ~25,000 queries per day at full rollout. Indexing pipeline: Document Upload → Type Detection → Preprocessing → Chunking → Embedding → Pinecone Query pipeline: User Query → Cache Check → Query Rewrite → Hybrid Search (BM25 + Vector) → RRF Fusion → Reranker → LLM → Response Two pipelines in