Pairing LLM reasoning with external retrieval so responses cite up-to-date, relevant sources instead of relying on model memory.
RAG is the main lever for freshness and factuality. PMs decide what corpus to expose, how to chunk and rank it, and how much to trust the retrieved facts. Done well, RAG reduces support load and legal risk; done poorly, it slows responses and confuses users.
Curate a clean, permissioned corpus. Choose chunking tuned to your queries, add re-ranking, and cap citations to the most relevant 3–5. Reserve prompt space for safety and instructions. In 2026, ship per-collection evals (answer correctness, citation precision) and degrade gracefully to model-only answers when retrieval fails.
A release-notes assistant uses RAG over changelog docs and support macros. After adding re-ranking and limiting to three citations, correct-answer rate jumps from 71% to 88% while latency stays under 1.3 s at p95.