I Broke RAG at 50K Documents. Here’s What Actually Works at 1 Million.

A no-fluff engineering guide to production RAG - the stuff I wish someone had told me before I wasted three months chasing the wrong bottlenecks. 1.1 Rag in production and where it breaks! Let me start with something nobody wants to admit: most RAG tutorials are useless for production. They embed 200 PDFs, hit 95% accuracy on a toy benchmark, and ship it. Then you come along trying to handle a million tickets, a decade of legal documents, or a sprawling enterprise knowledge base - and the whole thing falls apart in ways that are genuinely hard to debug. I’ve been through this.