Senior Technical Architect/ Full-Stack Engineer

Seeking a senior full-stack engineer / technical lead to architect and build a web application, working directly with the founder. Project specifics are shared with shortlisted candidates under NDA. Required skills and experience: React/Next.js; Node.js and/or Python; PostgreSQL; REST/GraphQL API design; LLM API integration and prompt engineering (OpenAI/Anthropic); document and OCR data extraction; third-party API and webhook integrations; payments; authentication and multi-tenant architecture; AWS/cloud deployment; automated testing, security, and monitoring. Must have shipped B2B SaaS products and be able to both architect and build independently.