does anybody think it's doable?
I wouldn't say that it's doable if you haven't sell your programming skills before. Although, you can try selling them as a freelancer. A site that offers you selling/buying such service is Fiverr, but it doesn't accept crypto last time I checked. Again, if you're new to this market you'll find many difficulties. It may take you months to start having a good earning, especially if we're talking about cryptos only.