Not op, but I've had good experience with WeasyPrint. I use it for generating PDF invoices: I create a HTML invoice from a template, WeasyPrint turns it into a PDF document. It handles CSS, images, custom fonts, etc.

A neat trick to convert HTML to PDF in a browser environment is to open a new browser window, load the HTML in it, and call print() on it, like here: https://stackoverflow.com/a/33890644/5821. May be OK for an internal tool.

puppeteer