Your Dashboard
Interview Coaching
Learn
System Design
ML System Design
Code
Behavioral
Salary Negotiation
Interview Guides
Leetcode 1396. Design Underground System
Design a system that records passenger check-ins and check-outs and returns the average direct travel time between two stations. The core challenge is maintaining active check-ins per passenger id and aggregated travel-time statistics (sum and count) per station-pair to answer getAverageTime queries efficiently.
Asked at:
Ramp
Axon
Question Timeline
See when this question was last asked and where, including any notes left by other candidates.
Late October, 2025
Axon
Senior
Police officers report their timed GPS location to a dispatch center. Implement a function for the dispatch center to find an officer's location closest to a given time.
Late July, 2025
Ramp
Mid-level
Comments
Hello Interview Premium
Your account is free and you can post anonymously if you choose.