About

Hey there! I’m Theo Nastos, a Senior Software Engineer and Technical Lead with expertise in AI Systems and Product Platforms, based in Athens, Greece.

I specialize in building scalable solutions using TypeScript and JavaScript. My focus areas include distributed systems, hexagonal architecture, and event-driven systems. I’m particularly passionate about AI/LLM tooling, including prompt engineering, RAG pipelines, structured outputs, and LLM observability.

Currently, I’m leading engineering initiatives at Causaly, focused on improving user engagement through AI-powered product features and internal LLM infrastructure. Previously, I led frontend architecture at Kariera Group and contributed to full-stack development at companies like Instashop (acquired by Delivery Hero), Moro Tech, and Moosend (acquired by Sitecore).

I hold a degree in Computer Science from the University of Thessaly.

Outside of work, I enjoy songwriting and music, snowboarding, and reading books.