intro practice · system design prompt
STAR: an unconventional idea
Write a STAR about a solution you proposed that was not the obvious one. Show why the obvious one was insufficient.
The mechanism
Most real innovation comes from refusing to accept a tradeoff that everyone else is taking for granted. The signal is not novelty for its own sake — it is finding the assumption you can credibly weaken.
Expected evidence
starStory() returns { situation, task, action, result, metric: { name, unit, before, after }, rejectedAlternatives (array of 2+ { option, whyInsufficient }) }. The checker enforces structure only: four distinct sections of 20+ words, action the longest, 150+ words total, before ≠ after, and the result section must name the metric and state its after value. Aim for 250-350 words — that is the interview bar, not the checker’s.Try this drill in the practice workspace →
Hints when you need them
- Anchor on a constraint nobody else was taking seriously.
- Show your cost-benefit, not just your conclusion.