I've picked up a 2 year Rosetta Stone subscription, installed Korean keyboards on everything, and ordered a keyboard cover. I live with somebody that speaks Korean so I have people I can practice with both written and spoken.
I've found r/Korean and the beginner's list (https://www.reddit.com/r/Korean/comments/rq3th/the_ultimate_beginners_resource_thread/).
What else would y'all recommend for developers and entrepreneurs learning Korean?