Is that the man who did the introduction to category theory for programmers. Although I never grokked it as much as I would like, I appreciated that video series, for trying to make the subject so accessible.
That was Bartosz Milewski, see bartoszmilewski.com .
No. This Bartosz is a fantastically talented IT person who, in their spare time, creates hand crafted interactive explanations of stuff. https://ciechanow.ski