That’s a great question. A good data engineer can spot for a data scientist on a good day, but also has distributed systems and devops experience. The broader circle that notionally encloses AI is “computer science”, so the data engineer overlaps some data science, some computer science. I left a lot off that diagram so I could focus on the AI bits, e.g. visualization, storytelling, business analysis.
A more useful explanation of where data engineering fits in is probably if we look at the lifetime of a data project and the skills required. That helps us understand where data scientists, data engineers, and business analysts all fit in.