Many modern web platforms provide features to export system data into PDF formats, such as billing invoices, accounting reports, and resumes. Behind the scenes, these document engines usually share a common architecture: they accept HTML code (or compile it from an application template) and render it into a PDF file using specialized libraries like **wkhtmltopdf**, **WeasyPrint**, **dompdf**, or headless browser instances like **headless Chrome (Puppeteer / Playwright)**.
