I was a teacing assistant for two courses in Carnegie Mellon University. The first was an introductory Python course, Principles of Computing. I TA'd this class for three semesters. I led a lab session every week for a group of 20 students, lecturing concepts like sorting and recursion. I also held office hours and sometimes exam review sessions.
I was also a TA for a graduate course, Mobile and IoT computing. This course was a project-based class where students formed teams to work on a IoT device of their choice. I advised students on Android and iOS programming, and also handled basic course logistics.
I kept working as a teaching assistant becasue I found getting myself ready to answer students' questions actually made me learn a lot.