I Replaced a $40/mo PDF API with 200 Lines of Web Worker Code — Here's the Offline Invoice Tool I Built

The bill that started this I was paying $40/month for a PDF generation API to power a tiny internal invoicing tool for a client project. Forty bucks a month to convert some JSON into a PDF. That's it. That's the whole service. I finally sat down on a Saturday to see if I could kill that subscription. Three weekends later, not only did I kill it —...