Web design is actually written like this in Ukrainian: "веб-дизайн" (with a hyphen)
Added to the TODO list.
"Web design - my hobby" seems like a more than adequate translation with at most a warning.
I don't think English is much known for sentences like "I Tom" or "Life not bed of roses".
In English, if we use a dash then leaving out "is" would be the best interpretation, in my experience. Is it different in Ukrainian?
Why the hyphen between веб дизайн and моє?
Are "Designing web is my hobby"
"To design web is my hobby"
Web design is a well-defined term and not just a compound noun, so you cannot replace it by a gerund or infinitive.
Graphic Design is my passion