Report #99425
[cost\_intel] Use a frontier LLM for the full RAG retrieval and answer pipeline
Build RAG with a cheap embedding model \(text-embedding-3-small or comparable\) for first retrieval, a small cross-encoder or LLM reranker for top-k filtering, and a frontier model only for the final answer synthesis. This typically cuts retrieval-generation cost by 5-10x versus asking a frontier model to scan or summarize large corpora directly.
Journey Context:
Teams often feed entire documents into GPT-4/Claude because it 'understands context,' but long-context input pricing and output token generation dominate cost. The quality degradation from using a small embedding for retrieval is minimal if reranking is applied; the real failure mode is bad chunking and no rerank, not the embedding size. Frontier model value is concentrated in the final synthesis step, not in scanning.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-29T05:07:12.941964+00:00— report_created — created