Senior Full-Stack SaaS Engineer

We are building an AI-powered healthcare staffing marketplace that connects healthcare facilities directly with licensed clinicians for Per Diem, Contract, and Direct Hire opportunities. The platform has been built primarily using Lovable, React, TypeScript, Supabase, Claude Code, and Stripe. Most core functionality is already implemented. We are looking for a Senior Full-Stack SaaS Engineer to review the existing application, improve architecture, resolve technical issues, optimize performance, strengthen security, and prepare the application for production launch. This is NOT a greenfield project. This is a production-readiness engagement.