Case study
Payments across five providers and three regions
Integrated and troubleshot payment gateways for products selling in the US, Latin America, and Saudi Arabia.
- 5
- payment providers
- 3
- regions: US/EU, LATAM, Saudi Arabia
The providers
- Stripe as the primary gateway for US and European clients
- PayPal as an alternative checkout
- Mercado Pago for Latin America
- Culqi for Peru
- Moyasar + Mada for Saudi Arabia, the most challenging of the set
What actually matters in payments
Getting a test charge through is the easy part. What I worked on:
- Idempotent webhooks. Webhook delivery is reconciled by event ID, so a retried event never charges or fulfills twice.
- Declines are data. I read soft and hard declines through issuer response codes. Soft declines get smart retries with backoff; hard declines don’t get retried.
- Keeping cards alive. Stripe network tokenization and Account Updater keep reissued cards working, so renewals don’t silently fail.
- Local methods beat card-flow tweaks. Local payment methods such as Yape in Peru and Mada in Saudi Arabia raise approval more than any optimization of the card flow.
- What I watch. Approval rate segmented by BIN, issuer, and country; funnel drop-off and cart abandonment; and p95 latency.
At Designli, the same lens applies in reverse: when I audit a prospect’s codebase, the payment integration is one of the first places I look for risk.