I've been fortunate to be born into a life where my basic needs are trivial to meet, and I've been able to create value way beyond what I need to live comfortably. Any excess beyond that will have negligible effect on me, but will provide huge marginal utility to people who aren't fortunate enough to be born into a situation like mine. So I don't feel like I can justify not donating it!
I like building things, especially with software. I've been fortunate enough that people also like to pay for some of the things I've built so far.