I'm in a similar position--plenty of technical experience (~15K hours of programming, founded 2 startups and built the teams, sold 1), but I'm not quite sure what I want to build next. I've been offered early positions at a lot of startups, but nothing has really grabbed me yet.

If you think you have an awesome idea (eg, customer validation in a reasonably large market for something that is 4x better than existing solutions and yet not impossible to build), send me an email (joshalbrecht@gmail.com), especially if it's in an area that I have lots of experience in (finance, manufacturing, or machine learning)