Shipping RAG Systems with Evals and Guardrails
Great RAG systems come from great data and feedback loops, not just model choice. Focus on:
1) Data prep and chunking
- Normalize, dedupe, and remove boilerplate.
- Chunk with structure-aware rules and overlap where helpful.
- Store source IDs so you can trace responses.
2) Retrieval tuning
- Start with hybrid retrieval (dense + BM25).
- Add reranking for higher precision.
- Keep freshness jobs so the index reflects your source of truth.
3) Evals that matter
- Offline: faithfulness, answer relevance, context precision/recall.
- Online: latency, cost, thumbs-up/down, and task success.
- Automate regression runs when prompts or data change.
4) Guardrails and safety
- PII/PHI filters and allow/deny lists.
- Refuse ungrounded answers; require citations.
- Add fallbacks (e.g., direct search) when retrieval confidence is low.
5) Observability
- Log prompts, retrieved chunks, model, latency, cost, and user feedback.
- Dashboards for P50/P95 latency, cost per request, and failure modes.
- Red-team regularly to catch jailbreaks and hallucinations.
Ship small, instrument everything, and iterate with evals to keep quality from drifting.
