But actually teaching to large classes of kids?
Some love it, some hate it. A 'real' school should not have large classes. My KG and lower primary grades vary between 5 - 17 children. My secondary English and Science between 8 - 17 students. The most kids I've taught in one class at a 'poor' school was more than 100 - actually lots of fun.
I prefer to teach ESL to the young kids because.. well.. I'm a lazy sod! Preparing ESL lessons for young students takes much less effort than planning a secondary grade Science class, with the requirement to do continual assessment, grading etc, homework blah blah blah.
Truth is, I only teach Science/STEM after the school boss realised that I knew way, way more about engineering, Maths,STEM, technology, internet, coding etc than any of her existing technical teachers, (I told her I only wanted to teach ESL to the young kids again this year, and I still do teach grades 3 and 4, but she added on the science, but also cut my in-class hours to only 14 hours a week, still with a full-time salary...)