I think i can handle this code by hand in fact it’s better than code I have handled by hand. (at a cursory glance.)

In my day - I think it was around 2000 – I was handed a 5000 line perl script that both responded to CGI bin requests to run a store and kicked off fulfillment of the orders. Inside that script, it had two 1500 line long subroutines that sometimes navigated internally via goto.

We refactored, and added new features while a profitable business ran on top of the code. You don’t get quite the velocity you do on good code, but it’s manageable.