Pros
I worked as a lab instructor for 8 months while being a student at NPU. It is good to work as teacher assistant or as lab instructor at NPU. You get a schedule of your lab sessions, prepare your own tutorial materials and have a fun teaching studednts with all your passion to share your knowledge. What I like is the fact that you get absolute freedom in terms of what you teach and how you teach.
Cons
The bad side is that due to the lack of attention of administration to education system quality, about half of the lab instructors are not qualified enough to teach students, as many of them do not know even the subject they teach or know partially. Almost any student can become a teacher assistant for major part of teachers, where for instance a student who bearly knows programming and does not understand what OOP teaches Java programming or C++ programming. That is sad of course.
So the problem is that administration does not check if students applying for being teacher assistant are knowledgable enough. To luck of administartion, many of responsible teacher assistants and lab instructors are trying not to allow unqualified students to become teacher assistants.