Payment System — Stripe
Idempotency under unknown outcomes, immutable double-entry ledgers in integer cents, saga orchestration with compensations, bank-file reconciliation, PCI scope, and multi-currency.
Idempotency under unknown outcomes, immutable double-entry ledgers in integer cents, saga orchestration with compensations, bank-file reconciliation, PCI scope, and multi-currency.
A limit order book in memory, LMAX-style single-threaded matching, market data fan-out to millions, buying power under T+1 settlement, and the audit trail regulators require.