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Lesson 11 of 15

44. Design Ride-Hailing with Surge Pricing (Uber / Rapido)

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The interview prompt
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44.1 What do you ask first?
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44.2 How big is this, really?
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44.3 What are the doors?
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44.4 What do we store?
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44.5 What does the whole system look like?
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44.6 How are location updates handled?
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44.7 How does matching work?
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44.8 How does surge pricing work?
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44.9 How does the trip state machine work?
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44.10 What would you say in the last five minutes?
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Score yourself
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Variations to practise
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Sources
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Code lab
44. Design Ride-Hailing with Surge Pricing (Uber / Rapido)

44.10 What would you say in the last five minutes?

3 min read+10 XP

Step 6: Wrap-up (5 minutes)

  • Bottlenecks: location ingestion (in-memory index per city, stream for history), road-ETA calls (cache popular ETAs, compute only for top candidates).
  • Single points of failure: none central: the index is rebuilt within seconds from incoming updates; matchers are stateless; trips DB has replicas per city.
  • Correctness: atomic assignment, idempotent trip events, quotes that lock prices.
  • Safety and trust: share-trip links, SOS, anomaly detection on routes (long detours), and fraud checks (fake GPS).
  • Next with more time: shared rides (matching several riders on one route), scheduled rides, driver earnings and incentives, and batch matching across a city.

Memory code: "Fresh positions, honest prices, one driver per trip, every state on record."