I had taken the class previously and received an "A" in the class. After I heard that our Graduate Teaching Assistant was leaving, I asked my professor if I could join in. She approved me as a UTA while still having another Graduate TA. Having the "A" in the class previously and continuing to study more material afterwards for certifications led her to hire me.

I spoke with my professor at the time to see if she had any opportunities available. She did have an opening, and knew my grades, so she allowed me to be a TA for my final semester.