Design a Donation Service with Reliable Payment and Payout Tracking
DoorDashSoftware Engineer · Onsite
Last updated
Design donation collection and charity payouts with a PSP, idempotent state transitions, durable ledger records, asynchronous provider events, and reconciliation.
Design a donation service that collects funds from users and sends payouts to charities. Include a payment service provider and handle payment failure, disconnection, and duplicate requests.
Constraints & Assumptions
Focus on technical payment state and reliable integration. Supported methods, currencies, payout timing, refunds, and charity eligibility requirements must be clarified rather than assumed. Do not equate a browser success page with settled funds.
Clarifying Questions
What state authorizes a charity payout? Can the provider report asynchronously? What identifiers support idempotency? How are failed or reversed collections and failed payouts reconciled?
Follow-up questions
- What if the provider commits but the response is lost? What if a webhook arrives twice or out of order? How do you prevent paying a charity twice while retrying a failed request?
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