Available now — reply within 24h (UTC+8)

Your payment flow is broken. I’ll fix it.

I’m a backend engineer who repairs broken payment integrations — Stripe, PayPal, Adyen, FPX and more. Silent webhook failures, double charges, stuck refunds: I find the root cause, not a patch. Fixed fee. You keep 100% of the code.

StripePayPalAdyenFPXGrabPayTouch 'n GoXenditMidtransRazorpayMollieBraintreeWebhooksBillingSubscriptions
Sound familiar?

The failures that cost you money every day

01 / webhooksPaid, but your system never finds out

Provider fires the webhook, your endpoint fails signature verification or crashes — orders stay “unpaid” and support tickets pile up.

02 / idempotencyCustomers charged twice

Retries re-submit the same payment, or a double-click fires two requests. Refunds become a daily ritual.

03 / environmentsWorks in test mode, explodes in live

Test/live keys, webhook URLs and event types mismatched. You only discover it after real money flows.

04 / refundsRefunds never reach the customer

Refund succeeds at the provider, but your status sync is broken — customers email you, money already left the account.

05 / billingSubscriptions renew, then immediately cancel

Failed payment retries (dunning) misconfigured, SCA/3DS flows broken, or invoices are created twice.

06 / support“It’s your code, not us.”

Payment providers only log their side. The gap between their logs and yours is where revenue quietly dies.

Services

What I fix

Every engagement starts with a root-cause diagnosis. I don’t guess — I read the logs, replay the events, and trace the code path that actually runs.

webhook rescue

Webhook pipeline repair

Signature verification, retries, event replay, dead-letter queues, event-type coverage. Make the provider’s events actually drive your business logic.

hardening

Double-charge & idempotency

Idempotency keys, atomic payment state machines, race-condition fixes so one order can never be charged twice.

checkout & billing

Checkout & subscription flows

One-time payments, recurring billing, invoices, SCA/3DS handling, dunning and failed-payment recovery.

migration

Gateway migration

Move from PayPal to Stripe, legacy to modern providers, or consolidating multiple gateways — without double-charging or losing customers.

disputes

Refunds & chargebacks

Refund/status sync, dispute automation, evidence submission so chargebacks stop being silent losses.

compliance

PCI & security basics

PCI-DSS scoping, tokenization done right, sensitive-data hygiene in logs. The boring stuff that keeps you out of trouble.

Pricing

Fixed fees. No surprises.

You get a quote before any fix work starts. Diagnosis credit applies to the Fix, so you never pay twice for the same problem.

Diagnosis
$99 one-time
Root cause, in plain language
  • 48-hour root-cause report
  • Affected code paths traced
  • Fix plan with exact estimate
  • NDA before access, read-only first
  • 100% credited toward the Fix
Start with diagnosis
Rescue Fix
from $499 per engagement
The most common choice
  • Code fixes implemented & tested
  • Webhook repair: typically $499–$899
  • Full checkout rebuild: fixed quote
  • Deploy support & verification
  • 30-day follow-up included
Get a quote
Flow Care
$149 /month
Ongoing payment health
  • Monthly payment-flow health check
  • Webhook & error-log review
  • 2 hours of fixes included
  • Priority response (24h)
  • Pause or cancel anytime
Ask about care

Payment: card via secure payment link (Visa/Mastercard, FPX, DuitNow) or bank transfer — instructions are on your invoice. Prices in USD; invoiced in USD or MYR.

How it works

From broken to billing, in four steps

Tell me what’s broken

Share symptoms, error logs, and your stack via the form or a short call. No prep required.

48-hour diagnosis

A root-cause report in plain language plus code-level detail, and an exact fixed-fee quote for the fix.

I fix it & prove it

Changes implemented with tests, so you review a clean diff. You own everything. NDA available.

Done — or cared for

Handover notes for your team, 30 days of follow-up free. Upgrade to Flow Care if you want it monitored.

Why me

An engineer, not an agency

You talk to the person coding

No account managers, no ticket roulette. One engineer owns your problem end to end.

SEA + global gateway experience

Stripe and PayPal, but also FPX, GrabPay, Touch ’n Go, Xendit, Midtrans, Razorpay — the gateways most Western contractors have never touched.

You own the code

No lock-in, no proprietary platform. Fixes land in your repository, in your stack: Laravel, Node, Python, Go, Rails, .NET.

No fix, no fee

If the diagnosis is wrong or I can’t fix it, you don’t pay for the fix. The report is yours either way.

UTC+8, overlapping with the world

Based in Malaysia (MYT). Morning overlap with Europe, evening overlap with the US — fast turnaround for both.

Safe by default

NDA signed before access, read-only scope first, sandboxed test data encouraged. Your secrets stay yours.

FAQ

Questions, answered

Is it safe to give you access to my code?
Yes. I sign an NDA before seeing anything, and access starts read-only. Most clients give me a sandbox environment and a repo with test keys only. You control the scope at every step.
Which payment providers do you work with?
Stripe, PayPal, Adyen, Mollie, Braintree, Square, Razorpay, Xendit, Midtrans, PayMongo, and Malaysian/SEA rails like FPX, GrabPay, Touch ’n Go eWallet, and DuitNow. If it has an API, I can probably debug it.
Which tech stacks?
Backend-focused: Laravel/PHP, Node.js, Python (Django/FastAPI), Go, Rails, and .NET. If your payment logic lives in a frontend SPA, I can still trace it via provider logs and the API surface.
How fast can you fix it?
Diagnosis within 48 hours of access. Most webhook and idempotency fixes are done in 3–10 business days. Full checkout rebuilds get a fixed quote after diagnosis.
What if you can’t find the root cause?
Then you don’t pay for the fix. The diagnostic report is yours to keep — often it still saves you days of digging. I only quote what I’m confident I can deliver.
I’m a solo founder with a tiny budget. Can we start smaller?
Yes — start with the $99 diagnosis. It’s the cheapest way to know exactly what’s wrong and what a fix costs. Many founders then fix it themselves with the report, which is fine by me.
Contact

Tell me what’s broken

Prefer email or a call? Either works. Attach logs, your provider dashboard screenshots, or a loom — the more context, the faster the diagnosis.

contact@payflowfix.dev 🕑 Mon–Sat, ~09:00–22:00 UTC+8 (MYT) ⚡ Diagnosis: $99 · credited toward your fix

NDA available on request. Read-only access first, sandboxed test data encouraged.