Interview Questions: Observability and Cost
- What belongs in a RAG trace?
- Why are aggregate dashboards not enough?
- How do you attribute token cost to product features?
- What operational signals reveal retrieval problems?
- How would you investigate a slow answer?
- What cost levers exist before changing providers?
- How should cache hit rate influence architecture?
- What quality metrics must be watched before cost optimization?
- How do you design a release gate for cost and quality?
- What is the senior engineering answer?
Senior answer
Instrument every stage, slice by route and tenant, compare against baselines, and optimize spend only when groundedness and supportability remain intact.