"Tell me about a recent prototype you built to demonstrate a new technology to a stakeholder. What problem were you trying to solve, how did you decide what to prototype, how did you get buy-in, and what happened afterward?"
This question tests whether you can use a lightweight prototype to reduce ambiguity, influence decisions without formal authority, and translate technical possibilities into stakeholder value. Interviewers want to see that you did not build a demo for its own sake, but instead identified the right audience, scoped the prototype around a real decision, and communicated trade-offs clearly.
It also reveals ownership and prioritization. Strong candidates show they understood the stakeholder's concerns, chose the smallest useful proof point, and handled skepticism or changing requirements constructively.
A strong answer uses one specific example with clear stakes, timeline, and audience. It should show why the prototype mattered, what you personally built and communicated, how the stakeholder reacted, and the measurable outcome — plus one lesson you took forward about prototyping or influence.