5 posts on RAG.
A Vapi + FastAPI + Qdrant health assistant for rural India. Most of the design work was prompt engineering, and the rest was a rotating key pool that lets a fistful of free-tier LLM tokens carry the load.
24 hours to build a support-ticket triage agent. The interesting parts weren't the retrieval. They were the fast-path rules in front of it and the regex grounding verifier behind it.
The end-to-end architecture of a privacy-preserving RAG at SAP Labs: preprocessing, HNSW retrieval, metadata pre-filter, PII redaction, generation, audit trail.
The recall-versus-memory decision behind a GDPR-compliant RAG at 2M docs. Why I stopped reaching for IVF-PQ, and what HNSW cost me past a million vectors.
Scrubbing PII at index time destroys recall on any query naming a public entity. Move it downstream. How DeBERTa, HNSW, and a cross-encoder fit under 2s p95.
