You don't need a TESOL certification upon hire--just experience teaching ESOL elsewhere. After a certain period of time working there, employees could take a certification course for free.
Cons
Pay is low, but if you teach the evening course a few times a week it is definitely livable.
Class maximum is 15 students, many students are both engaging and interesting, students come from nearly every non-English speaking country which is a valuable opportunity to meet people from virtually all countries, management is mainly supportive when conflicts with students arise
Cons
NO VACATION/PAID DAYS OFF, on national holidays school is closed but teachers receive no compensation, compensation is quite insufficient, very demanding 5-hour daily intensive classes, facilities are lacking/outdated, frequent confusion as to class size (students can be suddenly added/withdrawn at any point in each 4-week cycle), insufficient space for teachers to prepare for classes