Full-Stack Engineer for AI Client Portal

We need an experienced full-stack engineer to complete a 70%-built client portal using React 18, Node.js/Express, PostgreSQL, AWS, and OpenAI. Existing features include JWT authentication, client dashboard, S3 document uploads, and basic reporting. Key tasks include auditing the codebase, fixing unreliable uploads for files over 10MB, implementing admin/client role permissions across API routes, optimizing slow dashboard queries, securing OpenAI integration with server-side keys and cost tracking, and adding GitHub Actions CI, tests, and deployment documentation. Initial fixed-price task: audit and secure approximately 18 admin API routes, verify access control, and document results.