Capstone: A P2P Payment Flow

1. The Question

“Design a mobile flow for reviewing, approving, sending, and recovering a person-to-person money transfer.”

Assume the backend owns accounts, authorization, transaction policy, and a durable ledger, which records financial transactions. We design the mobile experience and required contracts, not a financial network. Completed means the backend-defined transfer outcome; it does not imply separate external settlement unless the contract says so.

Try your own design for ten minutes before reading the walkthrough.