Uber / Lyft — Notes

Functional

• Request ride, match driver, compute fare.
• Live tracking, ETA.
• Pay, rate, tip.
• Surge pricing.
• Driver onboarding, payouts.

Non-functional

• Dispatch decision < 5 s.
• Driver location lag < 3 s.
• 99.99% on hot path.

Capacity

• Millions of active drivers globally.
• 10M+ rides/day.
• Location ingests: millions/s peak.

Schema

• drivers(id, status, vehicle, ratings)
• presence(driver_id, cell, lat, lng, ts) Redis Geo / KV
• trips(id, rider_id, driver_id, pickup, drop, fare, status_history[])
• payments(...)

Trade-offs

• Centralized matcher simpler but bottleneck → matcher sharded by city / region.
• Eventual presence consistency is fine; double-assign protected by atomic update.
• Surge balances supply/demand but unpopular; cap and explain.

Refs

• Uber Engineering blog (Schemaless, Ringpop, Cadence, M3, H3 hex grid).
• Lyft engineering (Envoy origin) blog.
• ByteByteGo "Design Uber", Alex Xu Vol 2.