Erwin Hofman ( LinkedIn ) moved from building his own fast CMS to helping e-commerce agencies and merchants with web performance optimization as a Google Developer Expert. CSS @import . The pastThe performance impact of CSS @import was first documented by Steve Souders in 2009. Most common usage: web fontsThe analysis of @import usage across the web reveals a clear dominance of font-related services. The web performance community has known about @import ‘s impact for over a decade.