React / Next.js Developer | SaaS | Bug Fixes, Add Features & API Integration

We have an existing SaaS web application that needs a full stack developer to help fix issues, improve the product and continue shipping new functionality. The application is built with React and Next.js, with a Node.js backend. Some parts of the product are already in production, while other areas need cleanup, debugging or additional development. The work can include: Investigating and fixing bugs in React and Next.js applications Debugging authentication, user roles and permissions Fixing API and backend issues in Node.js Improving slow pages and application performance Building new dashboards and admin panels Adding Stripe payments and subscriptions Integrating third-party APIs and services Working with PostgreSQL, Supabase or other databases Fixing deployment and production issues Taking unfinished features through development and release We may also need help with applications that were initially built quickly with tools such as Lovable, Bolt or Cursor. In these cases, the goal is to understand the existing codebase, clean up the parts that need attention and make the application reliable enough for real users. Our current stack includes React, Next.js, TypeScript, Node.js, NestJS / Express.js, PostgreSQL, Supabase and AWS. Docker and GitHub Actions are used for deployment and CI/CD. You’ll work directly with the developer responsible for the project. We prefer someone who can investigate an issue independently, understand the root cause and recommend the right solution rather than simply patching symptoms. Experience with SaaS development, web application development, API integration and production React / Next.js applications is important. If you have worked on existing SaaS products, please share a few examples and tell us briefly what you were responsible for.