Pick a few random sites from the Gatsby showcase on their homepage and run them through webpagetest.org Simple Testing.
Re:Incremental Builds in Gatsby Cloud
by tomnipotent on Wednesday April 22, 2020 @06:57PM
(#22951110)
shopflamingo.com, ideo.com, ca.braun.com, and bejamas.io are all blazingly fast for me.
Re:Incremental Builds in Gatsby Cloud
by davidwparker on Wednesday April 22, 2020 @10:06PM
(#22952179)
Ideo has a pretty bad insight score (41):
https://developers.google.com/speed/pagespeed/insights/?url=...
First paint: 4.1 Seconds. Time to interactive: 11.5 Seconds.
I wouldn't say that's very fast.
Edit: I didn't check the other three.
shopflamingo.com gets 47
ca.braun.com gets 77
bejamas.io gets 96
So implementation dependent I guess
This has not been my experience, considering all HTML is ready to go from last byte so that other than blocking CSS, rendering can begin ASAP. At this point, no JS is required to interact with the page so things are generally pretty snappy while we wait for React hydrate to kick in.