Full-Stack Developer - AI SaaS Product in London, United Kingdom

I'm looking for an experienced full-stack developer to help maintain and prepare an AI-powered fashion SaaS platform for launch. The product allows users to upload a photo of themselves and a clothing item, then uses AI to generate an image showing them wearing it. Users can purchase credit packs through Stripe, spend credits on each try-on, and access their generated results in a private gallery.

The app is already built with https://jobeax.com/link/Z30sZYC3jcRenVso, React, PostgreSQL, and Stripe. Google sign-in is in place. The focus is on making the entire product reliable, from sign-in through to a finished try-on, and ensuring payments, credits, and uploads work correctly before we take real customer payments.

What you will do

- Keep the studio, gallery, pricing, and sign-in working as one product.

- Make sure a payment adds the right credit pack once, even if the confirmation arrives more than once.

- Keep balances correct when someone starts more than one try-on at the same time.

- Return credits when a try-on fails or never finishes.

- Turn away files that are too large or not photos, before any credits are used.

- Let people delete their photos and saved results.

- Leave payments, credits, and failed try-ons easy to check when something looks wrong.

What we're looking for

- Shipped a web app with user accounts, a database, and card payments.

- Worked with Stripe, including payment confirmations that can arrive more than once.

- Handled a user balance, or something similar, where a failed action had to be put right.

- Explained a problem in plain language and tested the cases a customer would actually hit.

Fashion experience is not required. Please apply with a short note, your expected salary or rate, and one product where money and a user balance were part of the work.