Turing Completeness, modulo universe size and life expectancy, you can build anything that can be computable with C++. I would suggest to build a product that

Turing Completeness, modulo universe size and life expectancy, you can build anything that can be computable with C++. I would suggest to build a product that you could sell to customers with such financial success that you could buy out those start ups, and being majority share holder, you would force them to hire you. (Obviously, you may have additional constraints, but you didn't mention any, so...)