Dan Sullivan is an O'Reilly author, educator, and data engineer and architect. He works on real-time data platforms for internet-scale analytics at Hydrolix. He also teaches data engineering and data science through LinkedIn Learning, Maven, Udemy and O'Reilly, and has written books on data engineering, cloud architecture and NoSQL databases, and a forthcoming book on simulation modeling from O'Reilly. His teaching focuses on the undocumented stack of skills data engineers need in the AI era, including the ability to frame problems, reason about domain knowledge, and verify and validate AI outputs. He holds a PhD in computational biology and builds his courses from the perspective of a working data engineer and architect.