Work with me

Fixed-price development you can start today — 100% in writing, no calls.

I build the software end to end: Amazon SP-API, e-commerce, WhatsApp automation, payment integrations, dashboards. You pick a package, pay 50% to start, and I send a scoped plan and a preview you approve before I finish. No meetings — specs, previews and async updates.

✓ No calls, ever ✓ Pay via Gumroad (card / PayPal) ✓ 50% to start, 50% on delivery ✓ Invoiced from Portugal (EU VAT)
Amazon's own developer team publicly validated my settlement-reconciliation approach on GitHub (issue #5353). I run 5 Selling Partner API integrations in production and a 115-endpoint platform handling data, payments and webhooks.

Fixed-price packages

Buy and I start. Reply to the receipt with your details and I come back with the scoped plan and timeline.

Amazon SP-API v0 → listTransactions Migration

$900 done-for-you
  • Every v0 call mapped to its listTransactions replacement
  • Reconciliation that ties to the payout — to the cent
  • Released vs Deferred handled; no double-counting
  • Delivered as a PR with tests, validated on a real settlement
Start this — $900 →

Shopify Conversion Sprint

$450 1 product page + 1 landing
  • Mobile speed: optimized images, Lighthouse in the green
  • Conversion clarity: above-the-fold value + clean path to checkout
  • Keeps your theme & brand; tested across devices
  • Changes documented so your team can reuse them
Start this — $450 →

WhatsApp Cart-Recovery Bot

$400 install & configure
  • Abandoned-cart trigger wired to Shopify or Stripe
  • Idempotent send — never a duplicate that burns your number
  • Official WhatsApp Cloud API or Evolution/Z-API — your choice
  • Pre-filled message + checkout link, opt-out respected
Start this — $400 →

Something else? Same way of working.

Integrations, bots, automations, dashboards, backend in Node.js or Python — fixed scope and price agreed upfront, then delivered in blocks you approve as they land.

How it works

01

You buy the package (or message me for a custom scope). 50% to start.

02

I send a scoped plan, then a working preview — you approve before I finish.

03

I deliver, tested, with the code and docs. 50% on delivery. All in writing.

Free tools (before you decide)

SP-API v0 Scanner →

Paste your integration; it flags every Finances v0 call that breaks on 28 Aug and shows the replacement.

v0 → listTransactions field map →

The full mapping and the reconciliation edge cases, one page, no sign-up.

Settlement reconciler →

Paste a settlement flat-file; it sums the lines against the payout and flags the no-order-id lines.