High Performance Websites and Even Faster Websites http://shop.oreilly.com/product/9780596529307.do http://shop.oreilly.com/product/9780596522315.do
These two on website performance are good, though they're a bit dated (pre http2 etc).
High Performance Browser Networking http://shop.oreilly.com/product/0636920028048.do
I never fully read this one but it's really good, probably required reading if you're serious about webdev
CSS: BEM/OOCSS/SMACSS methodologies, they make you think critically about the structure of you styles. Harry Roberts does good writeups on maintainable css.
I second Don't Make Me Think and I also liked Eloquent Javascript (that zoo has a bunch of new exotic animals since, so I don't know if it's the best bet. It's a fun book though)
If, in the unlikely case that your particular bit of brilliance is indeed hampered by the vestigial amount of overhead still present in contemporary HTTP, then you might do as Google and several other operations have done and dispense with traditional techniques (including TCP) altogether via QUIC.
Just because what you see in the Network tab of your browser's 'Developer tools' window looks like something from 2005 doesn't mean that's what is actually on the wire. It mostly isn't any longer as a share of global traffic.
But again, all of that is irrelevant; the post provided no evidence that replacing HTTP with some dubiously unnamed form of RPC would solve any actual problems. HTTP was tossed in the rant basket with a bunch of other things, few of which appeared relevant to the actual failure modes cited.
[1] https://www.oreilly.com/library/view/high-performance-browse... [2] https://github.com/http2/http2-spec/wiki/Implementations