Your question is Idempotency for Payment Transactions. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
How would you design an idempotency layer for payment transactions at Snapmint?
Focus on preventing duplicate debits across retries, timeouts, and partial failures while keeping the API fast and safe. Assume the solution must work for high-volume payment initiation and status-check flows, and be robust to client retries, webhook replays, and downstream gateway ambiguity.