Uber (ride matching)

Track a million moving drivers and match each ride request to a nearby free driver in about a second. The write path is a firehose of location pings; the correctness problem is never assigning one driver to two riders.

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Duration 45:00

Requirements checklist

Drivers send their location every few seconds.A rider requests a ride; the system finds nearby available drivers, offers the trip, and assigns exactly one driver.Track trip state (requested, assigned, in progress, completed).Matching decision within ~1 s of the request.Location updates are loss-tolerant: a newer one arrives seconds later.A driver is never assigned two concurrent trips.Survive the loss of a data centre: dispatch for a city must fail over.

Clarifying questions

How many drivers online, and how often do they ping?
Matching radius and time target?
Can a driver have pooled trips?
Is the system global or per city?

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requirements

Suggested time: about 6 minutes. Failover unit and trip state machine.

Notes for requirements