Digital Ocean just published my article on How to setup Review Ninja on a Digital Ocean droplet using docker-machine and CoreOS.
They have high standard for their articles, e.g., every step has to be crystal clear and assume the audience is blank slate. Their editors are technical. The editor I was assigned to was Brian Hogan who wrote the tmux book which I have read and loved a few years back. How cool was that! All in all, a good experience and I highly recommend writing for them if you have time.