Implementing the Mobile-First Paradigm

Now that our first Express application is usable, we act on the mantra of this age of software development: mobile-first. Mobile devices, whether they be smartphones, tablet computers, automobile dashboards, refrigerator doors, or bathroom mirrors, are taking over the world. 

Another issue is mobile-first indexing, meaning that search engines are starting to preference indexing the mobile version of a website. Search engines so far concentrated on indexing the desktop version of websites, but the growing popularity of mobile devices means search engine results are skewed away from what folks are using. Google says it is not fair to mobile users if the search result, which was derived from the desktop version, does not match the mobile version of a website. For Google's take, including technical tips on the markup...