U2xAI
…
Quality, Cost & Token Economics

Cost modeling and unit economics Interview Questions

25 questions. All 25 carry a written answer.

  1. #1Build the cost-per-interaction model for a feature with a 2,000-token prompt and a 500-token response.CalculationFoundational
  2. #2What cost drivers exist for an AI feature beyond model tokens?ConceptFoundational
  3. #3Explain how a RAG pipeline's cost structure differs from a single model call.CalculationIntermediate
  4. #4How does prompt caching change your unit economics, and when does it not help?CalculationAdvanced
  5. #5Model the monthly cost of a feature used by 50,000 users averaging 12 interactions each.CalculationIntermediate
  6. #6What is the cost impact of moving from a single call to a five-step agent?CalculationAdvanced
  7. #7Describe how you would find the most expensive one percent of your traffic.CaseAdvanced
  8. #8Explain the gross margin problem for AI products with flat-rate pricing.ConceptIntermediate
  9. #9How do you model cost when a small share of users generate most of the usage?CalculationAdvanced
  10. #10What levers reduce cost per interaction without reducing quality? Name five.ConceptAdvanced
  11. #11Describe the tradeoff between a cheaper model and more retries.CalculationAdvanced
  12. #12How do embedding and re-embedding costs enter a RAG cost model?CalculationAdvanced
  13. #13Build a sensitivity analysis for a cost model where token prices fall 40 percent.CalculationAdvanced
  14. #14What is the cost of your eval and monitoring infrastructure relative to serving?CalculationAdvanced
  15. #15Explain how routing between models affects blended cost.CalculationAdvanced
  16. #16How would you set an internal cost ceiling per user and enforce it?CaseAdvanced
  17. #17Describe the hidden cost of context window growth over a long conversation.CalculationAdvanced
  18. #18What is the economic argument for a smaller fine-tuned model over a large prompted one?CalculationAdvanced
  19. #19Critique a cost model that ignores failed and retried requests.Artifact critiqueIntermediate
  20. #20How do you forecast cost for a feature with no usage history?CalculationAdvanced
  21. #21Explain how self-hosting changes the cost curve and where the crossover point sits.CalculationAdvanced
  22. #22What should you do when a single enterprise customer becomes unprofitable?CaseAdvanced
  23. #23Describe how you would present unit economics to a CFO.CaseIntermediate
  24. #24How do you build cost guardrails into the product itself?ConceptAdvanced
  25. #25Walk me through the unit economics of an AI product I name.InterviewAdvanced