Loading...
Loading...
Browse 5 real-world technical and behavioral interview questions about Payments. Review scenarios, edge cases, and architectural best practices.
The control has to sit before the irreversible boundary, and the strongest one is that the payment is derived from a recorded obligation rather than typed and approved. Four eyes on the same screen is not a second opinion, and an out-of-pattern check that runs in the morning reconciliation is running after the money has gone.
Persist the order in a pending state before you touch the payment gateway, quote tax and shipping per seller shipment, authorise once behind an idempotency key, and commit the remaining steps through a transactional outbox and a saga whose compensations void the authorisation and release reserved stock.
Prevent a double charge on payment retry with an idempotency key tied to the purchase intent, a unique constraint, atomic charge recording, honest in-flight retry responses and settlement reconciliation.
Preventing double booking seats means claiming the seat before payment, not racing two payments and reconciling later. A short atomic hold serialises buyers, payment only starts for the winner, and uncertain payment outcomes are settled by reconciliation rather than silent expiry.
Authorise at checkout and capture when the goods leave, because an authorisation is a reversible hold and a capture is a refund waiting to happen; then set the fraud threshold from the full cost of a decline against the full cost of a chargeback, which usually means accepting more fraud than instinct suggests.