I’m following M121 course. I find the course done very well, but in some cases, the labs are difficult to deal with also because to solve them you need to use functions not covered by the relative lesson.
In some cases, it is frustrating not to be able to solve a lab by trying to use what was explained in the lesson.
E.g. in the lesson 2 lab to solve the problem, I’d use $setIntersection not easy to find.