Senior Full Stack AI Engineer

Valpo Agency, US-based digital marketing company, is looking for a Senior Full Stack AI Engineer to take full ownership of our AI-powered web applications. You will be the sole technical person on the team, working directly with the founder. This means you must be highly independent, capable of managing everything from frontend to backend to deployment — without a technical manager guiding you.

What you'll do:

• Own and maintain an existing full-stack application (React + Vite + TailwindCSS frontend, Node.js + Express backend, Supabase for database and auth)
• Integrate and manage AI models via APIs (OpenRouter, OpenAI, Claude) including speech-to-text/ASR processing
• Build new AI-powered tools, dashboards, and automation workflows from scratch
• Manage all DevOps: GitHub repositories, CI/CD, hosting (Railway), and database administration
• Create and maintain automations using Zapier and agentic AI tools (Manus)
• Translate business requirements into technical solutions — the founder is non-technical, so clear communication is essential

What we're looking for:

• 5+ years of hands-on full-stack development (React, Node.js, Express)
• Production experience with Supabase (PostgreSQL, Auth, real-time)
• Proven experience integrating LLMs and AI APIs into shipped products (not just training models)
• Strong DevOps skills: Git workflows, Railway/Vercel deployments, CI/CD
• Experience with third-party API integrations (Google Ads API, Google OAuth, analytics platforms)
• Self-directed and comfortable being the only developer on the team
• Excellent English communication — you'll be explaining technical decisions to a non-technical stakeholder

Nice to have:

• Familiarity with agentic AI tools (Manus, LangChain, Claude)
• Experience with audio processing (ffmpeg, speech-to-text pipelines)
• Zapier / Make automation experience
• Playwright or similar end-to-end testing frameworks