Product design question
How is the payment distributed between the app provider and Google? Design the system architecture.
- Product design
- Hard
Practice this question out loud. An AI interviewer asks it, follows up like a real interviewer would, and scores your answer. Type or speak.
Start a mock interview on this question · Mock interview from a job description
What this question tests
System design for a revenue-split and payout pipeline, the real mechanics behind an app store's commission model.
How to approach it
- Clarify: this is about how app store purchase and subscription revenue is split between the platform and developers, a well-known commission model.
- Identify the core components: payment processing to charge the user, a ledger recording the gross transaction and the split, and a payout system disbursing developer earnings.
- Design the flow: the payment is processed and held, a rules engine applies the commission split, varying by developer tier or subscription type, then the ledger records both shares.
- Address reliability: the ledger must be the source of truth with idempotent transaction recording, so a retried or failed payment never double-charges or double-pays.
- Address payouts: batch developer payouts on a schedule with reconciliation against the ledger, and clawback logic for refunds and chargebacks against the developer's share.
- Define success as payout accuracy, zero discrepancy between ledger and actual payout, and time from transaction to developer payout.
What a strong answer includes
- Grounds the answer in the real, known app store commission structure rather than a generic payments diagram.
- Explicitly designs for refunds and chargebacks clawing back the developer's share, an easy-to-miss correctness requirement.
- Treats the ledger as the system of record with idempotency, the key correctness principle for any financial system.
Common mistakes
- Designing a generic payment flow with no mention of the actual commission-split logic or developer payouts.
- Ignoring refunds and chargebacks, which meaningfully complicate the 'who gets paid what' logic.
Likely follow-up questions
- How would you handle a dispute between a developer and the platform over the split calculation?
- How would you audit this system for correctness at scale?
More product design questions
- Design a TV for a car.Google · Product design · Hard
- Design a refrigerator for the blind.Google · Product design · Hard
- How do you design a camera for the elderly?Google · Product design · Medium
- Redesign Twitter for eCommerce.Shopify · Product design · Hard
- How would you go about designing a new location sharing app for Google?Google · Product design · Medium
- How would you improve Google Home?Google · Product design · Easy
More questions from Google
Learn the skill behind it
Chapters of the AI PM course that teach what this question tests.
- Chapter 4: Discovery and strategy for AI products
- Chapter 7: AI UX and human oversight: design for a system that is wrong sometimes
- Chapter 14: Get the job: the AI PM interview loop