I had some passive income sources earlier but they all did not last forever and they took a lot of work to setup plus a quite a few never made any income. Don'

I had some passive income sources earlier but they all did not last forever and they took a lot of work to setup plus a quite a few never made any income. Don't fall for the ease implied by the word passive. This is a concept designed to sell self help books and promote gurus. What you can do as a software developer to make money requires effort and chasing something that does not is fooling oneself. A better perspective is to ask what can I do to generate the most income; and maybe put up with a bunch of obvious and boring answers.