The 60-second answer
Separate task quality, factuality/grounding, safety, latency, and cost instead of one aggregate score. Use representative held-out prompts plus deterministic checks where possible.
Build the answer in this order
1
Define the mechanism
Separate task quality, factuality/grounding, safety, latency, and cost instead of one aggregate score.
2
Explain the architecture
Use representative held-out prompts plus deterministic checks where possible.
3
Compare trade-offs
Calibrate human review or LLM-as-judge against reference examples and periodic audits.
4
Close with serving + evaluation
Track slice-level regressions and uncertainty across model or prompt changes.
A useful interview mental model
This is the shape of a strong answer—not a script to memorize.
01Definition
02Mechanism
03Trade-offs
04Failure modes
05When to use
Senior-level signal
- Design evals around real failure modes and adversarial cases, not benchmark averages alone.
- Prevent evaluation contamination and version datasets so improvements remain trustworthy.
What the interviewer is really testing
Understanding beyond prompting: architecture, retrieval, evaluation, inference, safety, latency, cost, and failure recovery.
Likely follow-up questions
What assumption makes this approach work?
When would you choose the strongest alternative instead?
What production or data failure mode changes your answer?
Common weak-answer patterns
- Reciting a definition without mechanism or assumptions.
- Claiming one technique is always better without a data regime.
- Stopping before failure modes, validation, or deployment implications.