Den Zubrytskyi
I ship AI features into production SaaS — from LLM integration to a fine-tuned classifier in production — backed by 9 years of end-to-end Rails product work.
Flagship project
Review Copilot
AI review analytics for Shopify merchants — solo-built, end to end. Full lifecycle ownership: scoping, ML model training, deployment, and App Store approval.
Includes a custom fine-tuned DistilBERT multi-label classifier served via a Python/FastAPI microservice alongside the Rails app.
Selected work
RevvedUp
AI-driven ABM SaaS with LLM-powered content generation running in production B2B.
MagicFlute
Greenfield MVP shipped solo in 3 months, with LLM integrations.
Knock Knock City / Cablook
Marketplace products — payments, geolocation, Dockerized deployments, APIs.
What I do
AI features for existing products
Adding AI capabilities to your product without hiring an AI team.
Senior full-stack Rails delivery
End-to-end product work: backend, frontend, infrastructure, shipping.
Rails upgrades & codebase rescue
Bringing legacy Rails apps back to a healthy, maintainable state.