Most were a while ago (hence the complacent part), but I made a hosting panel (those were popular little over 10 years ago) and sold that (made well over 100k$ in a few months), hosting company hosting millions of sites/apps, a proprietary CMS company, a company that sold games related stuff, a dating site, a PoS system+hardware and a bunch more things. They were all side projects at the time besides the CMS company (which managed to get to 400 staff before I sold) and all ran almost automatically after the onramp efforts. Also, and this seems a weirdo thing here on HN, if I had partners/co-founders (and with most I did), for almost all of these goes that I have never seen or even voice talked with them. I did not know them before, we met online and just assumed trust. We made good money just over text chat. And that's how I ran the CMS Corp as well (as cofounder/cto). I want to do that again in 2022.
Different per project; I sell best b2b and see consumers more as a wildcard/luck. But managed both.
And I knew what to build by talking to businesses or looking around on forums (I am old) what people ask for. Now Twitter and HN and reddit are pretty good to figure out what to create.
