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Problem Understanding
Restate the problem in your own words.
Design Uber (Dispatch & Trip)
Design an Uber-class ride-hailing system: riders request a ride, drivers nearby get an offer ranked by ETA, the chosen driver accepts, the trip lifecycle plays out, payment settles. The bones of the architecture are the geo-index (drivers update position at ~1 Hz), the dispatcher (matches rider → driver in seconds), and the trip state machine. Capacity is dominated by the geo-index write path — ~1M concurrent drivers × 1 Hz ≈ 1M writes/sec at peak — and surge pricing rides on top as a read-mostly multiplier.
- UberRiders + drivers globally, with H3-cell geo-indexing and a regional dispatcher per market.
- LyftSame problem, similar architecture; emphasis on shared rides was a deep-dive twist for years.
- Didi (China)Hyperscale Chinese version — 30M+ rides/day. Same dispatch + geo problems at greater density.
- Ola / BoltRegional players with the same architectural shape — the differences are payments and regulatory plumbing.
Your task: read the problem above, then write what the system is, who uses it, the rough scale, and the headline UX expectation — in your own words. Submit for AI review when you're ready.
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