Uber / Lyft / Ola — Simple#
Problem statement (interviewer prompt)
Design Uber / Lyft: riders request rides, the system finds a nearby driver in seconds, computes fare with surge, tracks the trip live, and charges on completion. Handle 10M+ rides/day, location pings every 1–3s, and dispatch decisions in <5s.
flowchart LR
R([Rider])
D([Driver])
DISP[Dispatch]
GEO[Geo Index]
PRICE[Pricing / Surge]
PAY[Payment]
R --> DISP --> D
D --> GEO
DISP --> GEO
DISP --> PRICE
R --> PAY
classDef client fill:#dbeafe,stroke:#1e40af,stroke-width:1px,color:#0f172a;
classDef edge fill:#cffafe,stroke:#0e7490,stroke-width:1px,color:#0f172a;
classDef service fill:#fef3c7,stroke:#92400e,stroke-width:1px,color:#0f172a;
classDef datastore fill:#fee2e2,stroke:#991b1b,stroke-width:1px,color:#0f172a;
classDef cache fill:#fed7aa,stroke:#9a3412,stroke-width:1px,color:#0f172a;
classDef queue fill:#ede9fe,stroke:#5b21b6,stroke-width:1px,color:#0f172a;
classDef compute fill:#d1fae5,stroke:#065f46,stroke-width:1px,color:#0f172a;
classDef storage fill:#e5e7eb,stroke:#374151,stroke-width:1px,color:#0f172a;
classDef external fill:#fce7f3,stroke:#9d174d,stroke-width:1px,color:#0f172a;
classDef obs fill:#f3e8ff,stroke:#6b21a8,stroke-width:1px,color:#0f172a;
class R,D client;
class DISP,GEO,PRICE,PAY service;