For proper early 2000s nostalgia, I reckon the backend should actually be Apache mod_perl, with the ".cfm" extension script aliased to Perl CGI scripts because management tell everybody "it's running on Adobe!"...
If you had enough rack space, mod_perl+Apache2 could scale to anything you needed. Hundreds of Gbps, hundreds of thousands of RPS. Inefficient, sure, but seriously flexible+performant and really easy to deploy. I miss the old stacks, as Nginx and the other httpds really suck in comparison (feature-wise) and Java is still such a huge PITA. I'd honestly rather use modern PHP than today's Java webapps.