Full-Stack MERN Developer to Complete Website and Upgrade React Native App

We are looking for an experienced full-stack MERN developer with OpenAI, agentic development, React Native and UI design experience. Our website is approximately 97% complete. The existing code is already in GitHub, and you will work directly in our repository to finish the website. You will then redesign and upgrade our React Native app with the relevant website features. Main work - Complete the payout and withdrawal features using the Stripe, Wise and PayPal APIs, including an admin review and approval flow. - Update the help sections and their AI agent, including its OpenAI integration. - Complete the documented feedback and website footer. - Fix any issues that arise and complete the remaining frontend, backend, user and admin functionality. - Adapt the website’s mobile version and improve its responsiveness across phones, tablets and desktop screens. - Deliver a fully functional website with working payment integrations. - Redesign and upgrade the React Native app with the new website features. - Migrate our customers from another website to the new site after completion. - Provide **eight months of post-launch support**. We will provide website designs and UI mock-ups where needed. Your primary task will be to implement them accurately in code. Some features may first be built in Lovable; you will need to review that code, adapt it where necessary and integrate it into the existing project. All development must be carried out in our existing GitHub repository, with changes committed there.

Requirements

Proven experience with React.js, Node.js, Express.js and MongoDB. **Portfolio or live project links are required.** - Hands-on experience with the OpenAI API and agentic development, including AI agents that can use tools, follow multi-step workflows and integrate with application data. - Strong understanding of RESTful APIs and familiarity with MySQL. - Experience with e-commerce platforms, shopping carts and payment gateways such as Stripe and PayPal. Wise payout experience is particularly relevant. - Experience developing React Native apps. - Strong responsive design and cross-browser compatibility skills. - Ability to work within an existing GitHub codebase and make meaningful commits. - Ability to work independently, meet agreed deadlines, communicate clearly and pay close attention to detail. - Flexibility to adapt when unforeseen tasks or issues arise.

Nice to have

Experience with TypeScript, Next.js or GraphQL. - Knowledge of AWS, Docker or CI/CD pipelines. - UI/UX design experience or familiarity with Figma. Deliverables - A Production-ready MERN completed website with working frontend, backend, user and admin features, adapted for mobile, tablet and desktop. - An upgraded help section and working AI agent. - Updated React Native app published to TestFlight / internal testing track, Appstore and Google play with the new site features fully integrated • Short hand-off document outlining setup, environment variables, and deployment steps - Customer migration to the new site. - Updated source code in our existing GitHub repository with meaningful commits. - Documentation covering setup, maintenance and deployment. - Eight months of post-launch bug-fix support. To apply, please share links to relevant MERN, e-commerce, React Native and OpenAI projects. Describe any Stripe, Wise or PayPal integrations and agentic applications you have built. Explain how you would assess the existing codebase and customer migration before providing a timeline and quote, and confirm that you can provide eight months of post-launch support ** New Freelancer is welcome**