So you have plumbing and software engineering skills. You know how plumbers are struggling with the internet-y side of things? Are you aware of the fact that plumber + {city} is worth $40-60 a click through Google AdWords? Are you aware of the fact that the vast majority of landing pages are none... as in suck badly and don't convert? See the gap you could fill with a solution? Reply and I'll get in touch with you for some ideas.