Design live location tracking like Uber
PremiumReal-timeMedium
- Geospatial indexing
- Geohash
- Location updates
Quick answer
This real-time interview question asks you to design live location tracking like Uber. Aim for a design that delivers updates to many users with low delay, then explain connections, fan-out, ordering and trade-offs. Interviewers want to see how you keep latency low, handle reconnects and stay correct under load.
The problem
Design live location tracking for a ride-hailing app like Uber or Ola. Drivers' phones report their position every few seconds; riders see nearby cars moving on the map before a ride, and their own driver plus a live ETA during it. The hard part is 600,000 location updates and 1 million nearby queries per second.
Dispatch (choosing which driver gets the ride) and pricing use the same location data but are designed elsewhere; this interview is about the location ingest and the live views.
What must the system do?
- Driver updates: Each active driver sends position, heading and speed every 4 seconds while online, every 1 to 2 seconds while on a trip.
- Nearby cars: A rider opening the app sees available cars within 3 km, refreshed every 5 seconds, and cars should look like they move smoothly.
How well must it do it?
- Freshness: A driver position shown on a map is at most 5 seconds old.
- Latency: Nearby query under 100 ms; trip updates reach the rider within 1 second.
What scale should you design for?
Use these numbers in your estimates.
The scale numbers unlock with this questionUnlock
Key concepts
- Geospatial indexing
- Geohash
- Location updates
- WebSocket
- ETA updates
- Battery aware sampling
How you’ll practise
- Requirements
- Estimate
- Connections
- Message flow
- Delivery guarantees
- Wrap-up
Lala, personalized to you, gives a hint when you ask and reviews your design when you are ready.
What do interviewers look for?
In any real-time design round.
- Clarifies latency, ordering and delivery guarantees
- Chooses a connection model with reasons
- Explains fan-out to many receivers
- Handles reconnects, missed messages and duplicates
- Plans for hot spots and sudden traffic spikes
- States trade-offs between consistency and speed
Questions people ask about this interview question
- Which design type is this question?
- It is a real-time question. You design live location tracking like Uber and explain your choices the way you would in an interview.
- Is this question asked at entry level?
- It is marked Medium. Entry-level engineers can practise it, but it expects you to reason about requirements and trade-offs, not only list components.
- What should I cover first?
- Start with who sends and receives updates, how fast they must arrive and what order matters. Agree on scope with the interviewer before you design anything.
- Can I practise it for free?
- It is a premium question. Sign up and unlock it once for 10 credits; it then stays unlocked. When you finish, Lala, your personalized AI mentor, can review your design for 30 credits.
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Updated · Written by the SevyDevy team