Senior Full-Stack Engineer, AI Expert(Long-Term)

I'm looking for a Senior Full-Stack AI Engineer to work with me on an ongoing SaaS product. The main focus will be building and integrating AI-powered features and agentic workflows into an existing production application. I'm looking for someone who has strong full-stack SaaS engineering experience and can work independently across the product — from understanding the requirement and designing the solution to building, integrating, testing, and deploying it. Experience with Fintech, ERP, e-commerce, or other complex business systems is a strong plus. You'll be expected to use modern AI development tools and coding agents such as Cursor, Claude Code, or similar tools to accelerate development while maintaining strong engineering standards. What You'll Do: Build and integrate AI/LLM-powered features into an existing SaaS application Develop across frontend, backend, APIs, databases, and AI/LLM integrations Build AI agents and agentic workflows with tool calling, API integrations, and multi-step task execution Work with OpenAI, Anthropic, Gemini, or similar LLM APIs Implement RAG, embeddings, vector search, structured outputs, and intelligent automation where appropriate Integrate AI features with existing business logic and third-party services Make architecture and technical decisions independently Work with and improve an existing production codebase Use Cursor, Claude Code, Copilot, or similar AI coding tools as part of your daily workflow Own features end-to-end from idea → development → deployment → iteration What I'm Looking For: 8+ years of professional software engineering experience Strong full-stack experience with React/Next.js + Python, Node.js, Ruby/Rails, or similar Proven experience building production SaaS applications Hands-on experience shipping AI/LLM features to production Experience with AI agents, agentic workflows, RAG, or LLM integrations Strong understanding of REST APIs, webhooks, databases, background jobs, and async processing Good software architecture and problem-solving skills Experience with Fintech, ERP, e-commerce, or complex business platforms is a plus Strong written English and ability to work independently Engagement: Long-term, ongoing contract Hourly through Upwork Remote We may start with a smaller scoped project to confirm fit before moving into ongoing work To Apply Start your proposal with the word: AGENTIC Please answer: What is one AI/LLM feature you personally built and shipped to production? Have you built an AI agent or agentic workflow? Briefly explain what it did. What SaaS, Fintech, or ERP product have you worked on, and what did you own? Which AI coding tools do you use regularly (Cursor, Claude Code, Copilot, etc.)? What is your preferred full-stack tech stack? How many hours/week are you available? What is your hourly rate? Please focus on real production experience, not tutorials or simple chatbot experiments.