Airbnb / Booking — Simple

Problem statement (interviewer prompt)

Design Airbnb / Booking.com: hosts list properties with calendars, guests search by location + dates + filters, view availability, get a quote, hold dates, pay, and confirm. Strict no-double-booking; dynamic pricing; guest-host messaging.

flowchart LR
  G[Guest]
  H[Host]
  L[Listing Service]
  SRCH[Search]
  AVAIL[Availability]
  BOOK[Booking]
  PAY[Payment]
  G --> SRCH --> L
  G --> AVAIL
  G --> BOOK --> PAY
  H --> L
  H --> AVAIL

    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 G,H,L,SRCH,AVAIL,BOOK,PAY service;