Design
Elevator System
Design an elevator system for a multi-floor building that efficiently dispatches elevators based on requests.
01 - Why interviewers ask this
A single elevator is the entry point to one of the most-referenced scheduling problems in CS — interviewers use it to gauge your instinct for state machines before escalating to the multi-elevator version.
02 - Where this system exists in the real world
You interact with this design every day.
Building elevator controllers (single-car dispatch logic)
Warehouse vertical lift and pallet-conveyor systems
Amusement park ride queuing and dispatch
03 - What you'll master
Solve this once. Know it forever.
Model direction, door, and request states cleanly
Queue and serve requests in a sensible order
Separate the state machine from the dispatch policy
04 - What you'll design
6 functional · 4 non-functional requirements.
Users press up/down buttons on each floor
5 more requirements inside
Sign in to unlock the full brief and start designing
05 - Companies that ask this
You may face this exact question in your next interview.
Ready?
Open the canvas.
Design it yourself.
See all requirements, use staged hints, run your code, and compare with community discussions - all on the same canvas.
Start SolvingMore in Infrastructure