Stepping into a Web Performance Engineer role at REI was quite daunting. Fortuantely, the legendary Harry Roberts was contracted to analyize REI’s performance shortly after I joined. He pointed out a surprising performance bottleneck on REI.com that stemmed from a technology which intended to improve performance. I learned a lot from him and did my best to capture what I learned in this blog post.
You’ll find diagrams, WebpageTest waterfalls and timelines, and some speculation about the future of HTTP early hints.