Yes, I think you definitely can. I'd approach it similarly to how one would approach freelance software development. 1. You already have a day job, and through

Yes, I think you definitely can. I'd approach it similarly to how one would approach freelance software development. 1. You already have a day job, and through your network, someone asks if you have time for side work. 2. You create some kind of a public portfolio that anyone can check out and market yourself to the type of clients you're interested in. Your work will be viewed by most companies as a vitamin, rather than a pain killer, in that it's nice to have but not but not solving the most critical business problem - and this is why most documentation sucks - but, with some persistence you'll find clients who put value on your service.