LLM Agents Interview Questions, issue 8, Mar 2, 2026
The Static Benchmark Trap
Senior AI Engineer interview at OpenAI, and the interviewer asks:
“Your multimodal agent hits a 95% success rate on static benchmarks like Mind2Web, but completely falls apart when we deploy it in a live OS environment. Why is it failing, and how do we actually measure true reliability?”
Don’t say: “The live OS has too much visual noise, or the DOM structure is different. We just need to fine-tune the vision encoder on more OS-specific screenshots.”
An agent that performs on curated demonstrations but collapses after one perturbation has learned sequence replay, not policy robustness.
The full answer, with the mechanism and the arithmetic, is for paid subscribers on Substack.