I’d avoid MOOCs. Accreditation seems to be the standard (I think UCB MFE has a good collection). Some programs won’t look at online credits. One approach - If you’re near a major city, try night classes. A lot of schools have some form of adult Ed / extension school. You can also register as a special student, and go to very early morning classes or night. If you really want to rip off the band aid, consider Baruchs prep program- U of Chicago has one as well, and maybe Berkeley? FWIW, I really struggled w working and part time study. In retrospect, I should have taken the hit all at once, left work a year earlier and banged out the pre-reqs at one go. On the bright side, the C++ course from this website is top notch, and respected by the top US programs.