Payment Gateway Architecture

A checkout-to-settlement architecture that emphasizes idempotency, security boundaries, and asynchronous reconciliation.

Key components

• Checkout client with tokenized payment collection
• API gateway enforcing auth, rate limits, and idempotency keys
• Payment orchestration service for auth/capture/refund flows
• Fraud and risk scoring service
• Ledger service for internal transaction state
• External PSP and banking integrations

What usually breaks first

• Missing idempotency handling can create duplicate charges under retries.
• Processor timeouts can leave the internal ledger and external payment state out of sync.
• Fraud service outages can force a risky fail-open or conversion-killing fail-closed choice.
• Webhook delivery failures can delay capture, refund, or chargeback updates.

FAQ

What is Payment Gateway Architecture?

A checkout-to-settlement architecture that emphasizes idempotency, security boundaries, and asynchronous reconciliation.

Which components matter most in Payment Gateway Architecture?

Checkout client with tokenized payment collection, API gateway enforcing auth, rate limits, and idempotency keys, Payment orchestration service for auth/capture/refund flows, Fraud and risk scoring service

What usually breaks first in Payment Gateway Architecture?

Missing idempotency handling can create duplicate charges under retries. Processor timeouts can leave the internal ledger and external payment state out of sync.