On a related note, I once used puppeteer and headless chrome in a docker image to generate PDF manuals from our web page documentation using the print to PDF feature of headless chrome.

I am not sure if it would be viable to use for thousands of PDF generation per minute but it worked great. I wasted a lot of time trying to find a good lib for HTML->PDF and they all kinda sucked in different ways. The only downside is that the chrome PDF api doesn't have a way to generate a table of contents with page numbers.