Sara Soueidan just published an article on her path to designing a theme switch. Among the many great points she is making in this post, I would like to highlight one particular quote:

It was important for me to make sure this demo is accessible even if it’s just a quick proof of concept for a talk. First of all, because the code for the demo will be public, so I have a bigger responsibility for making sure it’s accessible, because I wouldn’t want to spread any inaccessible code around, especially if there’s a chance people might be using it somewhere else.
Another reason I wanted this to be good is that I’ll probably want to reuse it for other components for my upcoming front-end components workshop.