You've inherited a .NET application where invoices are "generated" by writing HTML to temporary files, then calling Process.Start("SumatraPDF.exe") with command-line arguments to convert them to PDF. The code works, but deployment is fragile: the build process must copy the Sumatra executable to the output directory, antivirus software sometimes blocks the subprocess, and running integration tests requires tracking child process lifecycles. When you search "Sumatra PDF .NET integration," you find forum threads from developers attempting the same external-process approach, asking why there's no NuGet package, and discovering that Sumatra isn't actually a PDF generation library at all. This confusion stems from a fundamental category error. Sumatra PDF is a desktop application for viewing PDF files—a lightweight alternative to Adobe Reader designed for speed and simplicity. It's an excellent PDF viewer, but it has no programmatic API for creating or manipulating PDFs.…