From 10+ years ago when I worked at PayPay, webscr (the frontend at the time, where you'd log in) was a total of 2GB of C++ that would get compiled into a 1GB CGI executable, deployed over some ~700+ web servers.
Debug versions would never get compiled, as I'm told the resulting file was too large for the filesystem to handle.
Apparently a great deal of the code was actually inline XML.
They knew this was a bad pile of technical debt, too: at one point, a senior/staff engineer gave a company presentation where they brought a fanfold printout of the main header file for this monstrosity, and literally unrolled it across the entire stage.
Debug versions would never get compiled, as I'm told the resulting file was too large for the filesystem to handle.
Apparently a great deal of the code was actually inline XML.
They knew this was a bad pile of technical debt, too: at one point, a senior/staff engineer gave a company presentation where they brought a fanfold printout of the main header file for this monstrosity, and literally unrolled it across the entire stage.