// TOPIC
#payments
2 articles
◆◆◆AdvancedPayPalBlock
01Design a Digital Wallet (PayPal / Venmo / Paytm)
Hold balances, transfer money between users instantly, and never lose a cent. Double-entry ledgers, idempotent transfers, and strong consistency.
#interview#payments#consistency
21 min◆◆◆AdvancedStripeAmazon
02Design a Payment System (Stripe-style)
Move money correctly. Double-entry ledgers, idempotency keys, the authorize/capture/settle lifecycle, reconciliation, and why money never gets eventual consistency.
#interview#payments#consistency
20 min