What exactly should a Data Engineer know?

I've been interviewing recently and got a few offers. The highest paying one (in London) is paying £130k + 20% Bonus, which is pretty good for London.

I passed the 4 stage interview process which included a single Leetcode Medium, a short take-home presentation assignment, one tech question interview, and a behavioral interview at the end.

Anyway, not a single part of the interview asked Data Engineering questions, they asked mainly simple data science and system design questions.

The role …

data data engineer datascience engineer