Airbnb | System Design Round | Airbnb Wallet

Design airbnb wallet.
Features -

• User can see wallet balance
• user can see transaction history.
  -User can transfer money between wallet and his bank account

APIs -
vendor_transfer_id = create_transfer(account_number, routing_number, transfer_type, amount)

get_transfer_status(vendor_transfer_id)

Explained the design, he was more interested in what all services will be there, scalability, caching, reducing latency, Atomic transactions etc.

Which 2 parameter should this sytem follow in CAP theorem? I think it should be conistent and available but not partiton tolerant.

Suggestions from leetcode community are welcome :)