Full-Stack Developer for AI Chat App

Job ID: 39948350

Budget: $30 – $250 USD

MOST OF THE WORK IS COMPLETE, IT JUST NEEDS POLISHING

We’re looking for an experienced Full-Stack Developer to help complete our AI chat web app MVP built with Next.js and Supabase.
The core app is already functional — user authentication, chat logic, and credit system are done. We now need someone to finish the payment integration (Paddle) and handle final security and polish tasks.
What Needs to Be Done
Integrate Paddle payments (credit packs + subscriptions)
Build a simple billing page showing current credits and allowing credit purchases
Create a secure webhook endpoint to update user credits after payment
logging finances within database as well as the subscription amounts and details etc
Finalize security (RLS validation, rate limiting, input checks, token caching)
Improve error handling and add basic UI polish (loading, empty states, responsive)
Test payment and credit flows end-to-end

Deliverables - mvp saas

Tech Stack
Frontend: Next.js 16 (App Router), TypeScript, TailwindCSS
Backend: Supabase (Postgres + RLS)
Payments: Paddle
Ideal Candidate
Has prior experience integrating Paddle or Stripe
Strong understanding of API security and authentication
Suggest timeline
If you’ve built payment-based SaaS or chat apps before, this project will be straightforward.
Please include a short summary of your experience and estimated timeline or rate.