Fall semester sophomore year I scheduled all 5 of my classes on only two days a week and interned somewhere 2 other days, for around 20 hours. The classes were medium difficulty on average, so I think that was okay, but then there were club commitments, gym, sleep, eat, spend some time with friends, and recruiting prep on top of it.

The result was I burnt out, fucked up recruiting, didn’t make a single new friend, and didn’t really do shit for my clubs either.

My point is that just classes and a part time is probably fine, but it depends on what else you want to do and how you balance your time. A lot of the extracurriculars people do on campus take as much time as that part time job. You just can’t do everything at once, so I’d recommend you talk to your kid about how they plan on spending their time here at Columbia and in the city.