Google Certified Expert Teaches SQL and Data Analysis: Master Databases, Queries, and Data Analysis

Marian is definitely a superProf!
We worked together for a long time both for school subjects and for my professional training and I can say that when I say programming, I say Marian and vice versa. He is very clever, creative, vigilant and knows how to explain very clearly, as many times as needed (he simply knows when you don't understand and he is happy to try another method).
What I really appreciated about Marian was the fact that each subject was approached as if we were in a real situation, so he never aims only to help you solve a problem, but to solve it in the most optimal and professional way .
I met many computer science professors at college, but I can say that none of them explained as clearly and comprehensively as Marian does. He really is an IT guru, a programming encyclopedia :)
In addition, he is an empathetic and sociable person, he has a great general culture, so it is always a pleasure to work together.
I definitely recommend him, he is simply the best!