I have been a CTO and technical founding engineer at a couple startups for the last few years, mostly building other people's ideas. finally want to do my own thing but i'm stuck on something kind of embarrassing for an engineer: i can't pick what to build. the building part doesn't scare me. it's the "what" that's killing me. b2b, b2c, ai stuff, some vertical niche thing, micro saas, boring-but-profitable... they all sound fine when i think about them for five minutes and then fall ...