You will get a Stripe billing audit: every way it can lose money
Project details
Most billing audits are a code review with opinions attached. This one is
a list of the specific ways your money can go missing, ranked by how much
each one costs you.
I spent two years on the merchant subscription platform at Credit
Agricole, one of France's largest banks, where a duplicate webhook meant
somebody's money moved twice. We took offer deployment from about 90 days
down to 12. Before that, core banking payments: transfers, direct debits,
instant payments. I am a Stripe Certified Billing Developer, and the
reference implementation behind that credential is public, state diagram
and failure matrix included.
What makes this different from a general code review: I check your Stripe
account configuration against your code, not just the code. Retry and
dunning settings, webhook endpoint health, what actually happens on a
declined renewal. Most revenue leaks live in the gap between the two.
What I will not do: recommend a rewrite, tell you to modernise your stack,
or pad the report to look thorough. If your billing is sound, the first
line will say so and you will have paid for the certainty.
a list of the specific ways your money can go missing, ranked by how much
each one costs you.
I spent two years on the merchant subscription platform at Credit
Agricole, one of France's largest banks, where a duplicate webhook meant
somebody's money moved twice. We took offer deployment from about 90 days
down to 12. Before that, core banking payments: transfers, direct debits,
instant payments. I am a Stripe Certified Billing Developer, and the
reference implementation behind that credential is public, state diagram
and failure matrix included.
What makes this different from a general code review: I check your Stripe
account configuration against your code, not just the code. Retry and
dunning settings, webhook endpoint health, what actually happens on a
declined renewal. Most revenue leaks live in the gap between the two.
What I will not do: recommend a rewrite, tell you to modernise your stack,
or pad the report to look thorough. If your billing is sound, the first
line will say so and you will have paid for the certainty.
Programming Languages
JavaScript, Java, TypeScriptCoding Expertise
Performance Optimization, Security, DesignWhat's included
| Service Tiers |
Starter
$290
|
Standard
$490
|
Advanced
$790
|
|---|---|---|---|
| Delivery Time | 3 days | 5 days | 8 days |
Number of Revisions | 1 | 2 | 2 |
Design Customization | - | - | - |
Content Upload | - | - | - |
Responsive Design | - | - | - |
Source Code | - |
Optional add-ons
You can add these on the next page.
Extra fix implemented
(+ 2 Days)
+$150
30-day follow-up support
+$180
Additional Revision (preset)
(+ 1 Day)
+$90About Mohamed
Stripe Billing & Subscriptions | Webhooks, Dunning, Proration Fixed
Paris, France - 3:52 am local time
payment, the duplicate webhook, the proration nobody tested — and by
then it's your customer's money.
Stripe Certified in Payments and Billing. Two years on the merchant
subscription platform at Crédit Agricole, where we cut offer deployment
from 90 days to 12. Before that, core banking payment flows, where being
wrong was a regulatory event rather than a bug ticket. Today I lead cloud
migration and production API integration at Air France-KLM. I bring that
standard to smaller products.
WHAT I'M BROUGHT IN FOR
Stripe and subscription billing — checkout, subscriptions, trials,
proration, upgrades and downgrades, failed payment recovery, dunning,
invoices, webhooks, Stripe Tax and EU VAT for digital products.
Billing that already exists and misbehaves — duplicate charges, webhook
events arriving twice or out of order, subscription state drifting away
from Stripe, revenue leaking through untested edge cases, reconciliation
between Stripe and your own database.
AI-BUILT MVPs TAKEN TO PRODUCTION
Apps generated with Lovable, Replit, v0, Cursor or Claude Code that work
in a demo and fail with real users. Auth, row-level security, secrets
handling, payment state, error handling and the webhook layer are where
they break. Usually hardening, not a rewrite — you keep what you built.
The same applies to n8n and Claude or OpenAI workflows that have to
survive duplicate events, retries, rate limits and idempotent processing.
STACK
Next.js, React, Node.js, TypeScript, PostgreSQL, Supabase, Stripe, n8n,
Docker, REST APIs.
HOW I WORK
Fixed scope and fixed price wherever the work allows, so there's no open
meter. Before I change any code you get the failure list in writing,
ranked by what each item is costing you. That document is yours whether
or not you hire me for the fixes — hand it to any developer. Every
reliability claim I make has a test behind it that you can run yourself.
WHAT I DON'T DO
No Shopify or WooCommerce plugin work. No pixel-perfect Figma builds. No
open-ended staff augmentation. If that's what you need, I'm the wrong
hire and I'll say so in the first message.
START SMALL
Send me your repo or a screenshot of your Stripe dashboard and I'll tell
you what's actually wrong before you spend anything. If you'd rather buy
the answer in writing, the Billing Audit below is that conversation,
delivered in 48 hours.
Steps for completing your project
After purchasing the project, send requirements so Mohamed can start the project.
Delivery time starts when Mohamed receives requirements from you.
Mohamed works on your project following the steps below.
Revisions may occur after the delivery date.
Access check and scope confirmation
I confirm I can read the repo and the Stripe account, then send you one line on what I will and will not look at. If the codebase is larger than expected I tell you before starting, not after.
Static pass: webhook handling, idempotency, state model
I read the billing code end to end: signature verification, idempotency, subscription state transitions, proration, and every place your database and Stripe can disagree about what a customer is paying for.