Petros K.
Senior Ruby on Rails, React & AI Engineer
Senior Full Stack & AI Engineer helping startups turn AI ideas into production-ready products. I work with founders building SaaS platforms, AI copilots, automation systems, and LLM-powered workflows that need to actually work in the real world — not just look good in demos. Over the past years, I’ve helped design and ship systems involving: • AI assistants & multi-agent workflows • RAG pipelines with pgvector / vector search • Automation & orchestration systems • SaaS platforms with real users and scaling needs • Backend-heavy architectures with Rails & FastAPI • React / React Native applications • AI integrations using OpenAI, Anthropic, LangChain, and modern tooling What clients usually value most about working with me: • Strong product thinking, not just coding • Ability to move fast in ambiguous startup environments • Clear communication with founders & product teams • Focus on maintainable architecture and long-term scalability • End-to-end ownership from idea → production Tech stack includes: Ruby on Rails, FastAPI, React, React Native, PostgreSQL, Supabase, Sidekiq, Celery, Redis, LangChain, OpenAI APIs, vector databases, AWS, Docker, and modern AI infrastructure. If you’re building an AI-powered product and need someone who can combine engineering, architecture, and product execution — let’s talk.
Earnings and projects
Last 6 months ÷ 6
Last 6 months: $9.2k
Billed in all: $60,949$61k
$9.2k in the last 6 months
Across 2 contracts
Across 7 contracts
Earnings, last 30 days
Skill rankings: Top 7% in Sass
Ranked by MRR among everyone on Upwork with the skill.
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- #14AWS CodePipeline154 freelancers · 🇬🇷 #1Top 9%🇬🇷#1 of 1
- #92Sass1,305 freelancers · 🇬🇷 #2Top 7%🇬🇷#2 of 8
- #164Ruby on Rails1,811 freelancers · 🇬🇷 #1Top 9%🇬🇷#1 of 3
- #468Git5,766 freelancers · 🇬🇷 #2Top 8%🇬🇷#2 of 20
- #535LangChain3,821 freelancers · 🇬🇷 #1Top 14%🇬🇷#1 of 5
- #575FastAPI4,337 freelancers · 🇬🇷 #2Top 13%🇬🇷#2 of 7
- #661Supabase4,116 freelancers · 🇬🇷 #2Top 16%🇬🇷#2 of 8