Paul Iusztin is a Romanian ML engineer and AI educator, the author of LLM Engineer's Handbook (Packt) — one of the more widely-read modern textbooks on production LLM engineering — and the host of the Decoding ML newsletter. His material focuses on the engineering side of taking LLMs from notebook experiments to production systems.
His CourseFlix listing carries two Paul Iusztin courses: LLM Engineer's Handbook (the book / course companion) and the Agentic AI Engineering Course. Together the courses cover the production-engineering arc from training and fine-tuning LLMs through deploying agentic systems.
Material is paid and aimed at engineers picking up production LLM and agentic-system work as a serious skill rather than dabbling. For broader content, see CourseFlix's LLMs & Fundamentals and AI Agents category pages.