Developer Needed to Fix, Harden & Extend an Existing AI-Built Web App

We have a web application that was initially built with the help of AI coding tools (Codex, Claude). The core functionality is in place, but it now needs a professional developer to review, fix, and improve it before it's ready for real-world use. What we need: Review the existing codebase and fix bugs/issues Improve security and harden the system (proper auth, data validation, error handling, etc.) Clean up and optimize code where needed (AI-generated code often has inconsistencies) Integrate additional AI features into the application Ensure the app is stable, production-ready, and maintainable going forward Ideal candidate: Strong experience with modern full-stack development Comfortable reading and refactoring existing code (not just building from scratch) Experience working with AI APIs/integrations Can identify security gaps and fix them without breaking existing functionality Communicates clearly and provides updates as work progresses