One of the most valuable books you can read for your career, in my opinion. The only other one is Designing Data Intensive Applications. (I used to have a few more but I'm narrowing down to just these two.)
Doesn't that rather depend on what your career is? Not everyone on HN is some sort of web developer.
If you interact with a network, it's relevant for you. :) Which is almost every type of developer.
I interact a lot with a network but that network isn’t the internet and I don’t really interact with web browsers. I think that’s true for plenty of people too, even those who work at big website companies like Facebook or Amazon or Google. That said, networking knowledge does matter and maybe this book imparts some ways to think about more general networking problems, though nothing excited me when I skimmed the table of contents.
Every developer deals with a compiler in some way, therefore "Compilers: Principles, Techniques, and Tools" is the most valuable book you can read for your career :-p