Available from Q4 2026 · contract or fixed price

Your hire takes six months. Your roadmap can't wait.

A senior engineer who works with AI agents and owns what they ship. You get the speed of agents with the judgment of someone who has run payments in production. I built and run a six-app platform this way, alone.

Jimmy Hwang, Berlin
Senior product engineer

Send a brief, 60 seconds See my work

Remote: EU hours or US East Coast overlap On-site in Berlin B2B invoice, EUR or USD

partyx.info/console

Admin console I built: money coming in, refund requests and a dispute to answer

Payments liveStripe, checkout to refund

One person on callTwo years. No outsourcing

6apps built and run alone

3enterprise sites on my console, every shift

2years running live payments

3languages: English, French, Korean

Why me, not the usual options

Three ways to fill the gap. One person who has already done the hard part.

Instead of an agency

The person on the call writes the code

You pay for a team, the work goes to whoever is free
One senior engineer, from the first call to production

Instead of more AI tools

Agents write it. Someone has to own it.

More licences mean more pull requests, and nobody who answers for them
I direct the agents, review what they write and answer for what ships

Instead of waiting for a hire

Starts in weeks, ends cleanly

Months to find, a notice period on top, then onboarding
Contract starts fast and hands over when your permanent hire arrives

Start with two paid days.

One real ticket from your backlog. You see the code, the review notes and the questions I ask. Then decide.

Book a trial

The operator console I own at WiTTRA Networks is used every shift at Stockholm Arlanda Airport, Eramet and ArcelorMittal.

How I work

AI writes the code now. The job is knowing when it is wrong.

The bottleneck moved

Review, not typing

With agents in the loop, pull requests run about 50% larger and wait around four times longer for a reviewer. I am the reviewer who also ships: agents draft, I own every line that reaches production.

Where agents fail

The unhappy path

They build the checkout that works and miss the refund that should not be allowed. PartyX's payments, payouts and refunds are exactly that code, live for two years with real money on it.

Why one person is enough

Deciding, not generating

Six apps in 22 months is not typing speed. It is choosing what to build, what to reject and what to delete, then carrying the pager for the result.

Why it matters 45% of AI-generated code ships with a known security flaw (Veracode, 2026). Someone has to catch it.

Fixed price

Need payments or ticketing built, not a contractor?

The same system PartyX runs on, scoped in writing before any work starts.

Payments and ticketing backend, built for your product.

Checkout, refunds, payouts and the ledger behind them, on Stripe, in your stack. The unhappy paths included, because that is where money goes missing.

ScopeA scoping call, then a written scope and a fixed price.
BuildCheckout, webhooks, refund rules, with regular demos on your staging.
HandoverPayouts, ledger, tests, runbook, and a handover session with your team.

From €20,000Fixed price and payment terms, set in the written scope.