> core AWS infrastructure is still heavily dependent on Perl scripts mashed together 15+ years ago

What part of the infrastructure? The control-plane logic that triggers when the dashboard/CLI/CloudFormation request modifications to resources?

I never worked with it directly so this may not be totally accurate, but IIRC a lot of the fundamental networking code for managing data centers -- DNS, traffic routing, etc -- was legacy Perl scripts. While I was there, at least one major us-east-1 outage was directly linked to a problem with one of these scripts.