Product design question

Design an elevator.

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What this question tests

Fundamentals of product design applied to a familiar physical system: can you reason about safety, throughput, and accessibility trade offs rather than listing generic features.

How to approach it

  1. Define the context, assume a mid rise office building elevator, since building type changes the design priorities significantly.
  2. Identify core needs: safety (reliable stopping and emergency systems), throughput (minimizing wait and travel time during peak hours like morning arrival), and accessibility for wheelchair users and those with visual impairments.
  3. Prioritize safety first as a non negotiable baseline, then throughput, since elevator wait time is the most common daily frustration in office buildings.
  4. Design for throughput: destination dispatch, where users select their floor before boarding so the system groups riders efficiently, reducing stops per trip.
  5. Design for accessibility: audio floor announcements, braille buttons, and adequate door hold time, built in as standard, not optional add ons.
  6. Define success as average wait time during peak hours and safety incident rate, not just a smooth ride feel.

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