You will get a reliability audit of your payment integration
Project details
I spent 6+ years in fintech at Xendit, one of Southeast Asia's largest payment
providers, where I owned the Cards domain and built the Payments API. I know exactly
where payment integrations quietly break.
Send me your payment setup and I will review it, then give you a clear, prioritized
report.
What I review:
• Your payment gateway integration (Stripe, or another)
• Webhook handling: signature checks, idempotency, retries
• Checkout or payment flow
• Refunds, error handling, and edge cases
• Reconciliation, and how you detect missing or duplicate transactions
What you get:
• A written report of what is risky and why
• Where transactions could drop, duplicate, or double-charge
• Clear, prioritized fixes you or your team can act on
• A short call to walk through it if you want
Perfect for: startups and SaaS teams who added payments quickly and want an expert to
confirm it is safe and reliable before it costs them money.
This is a low-risk way to get a payments specialist's eyes on your system. It is
stack-flexible, since this is review and recommendations, not writing production code.
Message me before ordering if you want to confirm scope. I respond quickly.
providers, where I owned the Cards domain and built the Payments API. I know exactly
where payment integrations quietly break.
Send me your payment setup and I will review it, then give you a clear, prioritized
report.
What I review:
• Your payment gateway integration (Stripe, or another)
• Webhook handling: signature checks, idempotency, retries
• Checkout or payment flow
• Refunds, error handling, and edge cases
• Reconciliation, and how you detect missing or duplicate transactions
What you get:
• A written report of what is risky and why
• Where transactions could drop, duplicate, or double-charge
• Clear, prioritized fixes you or your team can act on
• A short call to walk through it if you want
Perfect for: startups and SaaS teams who added payments quickly and want an expert to
confirm it is safe and reliable before it costs them money.
This is a low-risk way to get a payments specialist's eyes on your system. It is
stack-flexible, since this is review and recommendations, not writing production code.
Message me before ordering if you want to confirm scope. I respond quickly.
Programming Languages
JavaScript, TypeScript, GoCoding Expertise
Performance Optimization, Security, DesignWhat's included $120
These options are included with the project scope.
$120
- Delivery Time 5 days
- Number of Revisions 1
Optional add-ons
You can add these on the next page.
Fast 3 Days Delivery
+$60Frequently asked questions
About Zaki Arrozi
Payments & Backend Engineer | Integrations, APIs, TypeScript & Node.js
Jakarta, Indonesia - 11:52 am local time
14+ years in software, most of it in fintech. At Xendit, one of Southeast Asia's largest payment providers, I owned the Cards domain end to end, built the Payments API, and led a 9-engineer team across 8 markets.
What I can help with:
- Payment integrations: gateways and processors (Stripe, CyberSource, and more), with webhooks, retries, and idempotency so you never double-charge or lose a transaction.
- Checkout and billing: checkout flows, subscriptions, and recurring billing.
- Backend and APIs: event-driven systems (Kafka), clean APIs, and databases (PostgreSQL, Redis) built to scale.
- Reliability: reconciliation, monitoring, and architecture for systems that handle money.
- Frontend when needed: fast, lightweight sites and performance optimization (Astro, React).
Key experience:
- Built Xendit's unified Payments API (TypeScript and Go), putting every payment channel behind one interface.
- Owned the Cards domain end to end, including PCI DSS scope.
- Led a team of 9 engineers and scaled card acceptance from 1 to 8 markets across SEA, Hong Kong, and Mexico.
How we'll work together:
1. A short call to understand your product, users, and goals.
2. I map the scope, the trade-offs, and a clear plan.
3. I build and ship in steps, with checkpoints you can follow.
4. I support the launch and keep communication simple throughout.
I'm a good fit if you're:
- Building or fixing a payment integration, checkout, or billing flow.
- Scaling a backend that handles money and can't afford dropped transactions.
- Looking for someone who explains the trade-offs clearly, not just writes code.
Stack: TypeScript, Node.js, Go, PostgreSQL, MongoDB, Redis, Kafka, AWS, Docker, Kubernetes.
If you're building or fixing anything payments-related, send me a message and let's talk it through.
Steps for completing your project
After purchasing the project, send requirements so Zaki Arrozi can start the project.
Delivery time starts when Zaki Arrozi receives requirements from you.
Zaki Arrozi works on your project following the steps below.
Revisions may occur after the delivery date.
Review your requirements
I’ll review your architecture, code, and goals before starting.
Analyze your payment integration
I’ll inspect the payment flow, API usage, webhooks, security, and error handling.