I have countless times inspected packets on the wire when writing web applications, and there is tons we do to ensure service behaviour aligns with the networking stack.
I have also inspected traffic when investigating/writing patches for server code or the kernel, but that’s a completely separate matter.
What’s more, most nontrivial application code causes additional network activity, from DNS queries to database connections, calls to external APIs et cetera. The all-the-world-is-HTTP fallacy is how wheels get reinvented, but badly, as with websockets or JWTs.
I have also inspected traffic when investigating/writing patches for server code or the kernel, but that’s a completely separate matter.
What’s more, most nontrivial application code causes additional network activity, from DNS queries to database connections, calls to external APIs et cetera. The all-the-world-is-HTTP fallacy is how wheels get reinvented, but badly, as with websockets or JWTs.