1 min lesson
Why evals are the differentiator
Describe the practical point in "Evals are what turn a flaky demo into a system a senior engineer will run unattended", then say what it changes.
Step 1 of 2
Every FDE loop bends toward one question: how do you know it works? For most roles that's a follow-up. For this one it's the whole interview wearing a different hat.
A Forward Deployed EngineerAn engineer who embeds inside a customer's own engineering org to scope ambiguous problems and ship production-grade Cursor workflows a senior engineer keeps using after they leave. Press Enter for the full definition. at Cursor ships a code-modifying agent into a customer's repo and then has to convince a skeptical senior engineer to trust it on their production code. That engineer has seen confident demos collapse the moment they touch a real codebase. The only thing that moves them is a number they can check.
Hand-waving here is the most common way strong candidates lose offers. They build something that works in the demo, present it well and then go quiet when asked to prove the success rate. The interviewer doesn't hear modesty. They hear a person who can't tell a working system from a lucky one.
Evals are what turn a flaky demo into a system a senior engineer will run unattended. Without them you have an anecdote. With them you have a contract: this workflow does X correctly on Y% of these tasks and we'll know within minutes if that drops.