In this article I cover everything you need to know about the algorithm shifts happening at Google as they split the mobile and desktop search index. Many sites at the time, were not mobile-friendly (and many today still haven't done the work). This impacts visibility in search and can dramatically impact a site's performance across different types of devices. This article also takes a look back at some of the major Google updates over the years and how its impacted the overall search market. 

Read the article: https://www.vincidigital.com/make-hay-go-mobile-while-the-sun-still-shines-on-your-search-traffic/

Google's Mobile-Friendly Test Tool: https://search.google.com/test/mobile-friendly