The program did not initially allow remote TAs, but they started allowing it after a year or two. The latest data I’ve seen is that about 50-60% of the TAs are also OMSCS students and the rest are from the resident program in Atlanta. It was my experience that GT professors preferred to have a senior TA or head TA from campus (usually one of their PhD students), but they were comfortable letting most of the graders be remote. Some online TAs earn a reputation for being awesome and wind up as head TAs, and some profs don’t mind having fully remote teams, etc., but that’s the gist of it.

TA quality is highly variable.

Some of them are amazing, some of them are totally worthless.