This is a pretty cool article.
Wojciech Dobry is a designer and using a platform called Dribble he tracks 8-years of trends in the way buttons are designed for websites.
Web design is growing at an incredible pace, and styles seem to change from month to month. In just a few years, we have gone from text links to skeuomorphism to flat design. Navigation is one of the most important elements of web design, and the call to action button is its strongest tool.
Check out the article here: https://www.toptal.com/designers/ui/button-design-dribbble-timeline