Hands down the best class I've taken at Columbia. It's a one week intensive class that takes 16+ hours a day for 3 credits over winter break. You form a team in the Fall semester and apply online. If selected, you get to do customer development for your business idea, build an MVP, have to talk to over a 100 people and iterate on your business model canvas. Hopefully at the end of this you have a possible startup idea that has validated initial hypotheses. This class will challenge you but also teach you how to go about starting a business.
Don't take this class unless you're 100% interested in entrepreneurship and starting a company. It's a waste of your time and everyone else's time too! Useless team mates were a liability. Pick your team wisely. I now at least one team from this class that has gone on to raise over $2M in funding in the past.
Grading is pretty arbitrary. Take it P/F.