Why Microsoft Office Interop Fails for PDF Generation in .NET (And What to Use Instead)

Microsoft Office Interop is still widely used for PDF generation in .NET because it feels like a quick win. It works on a local machine, requires minimal code, and produces accurate results by leveraging Microsoft Office itself. The problems start in production. Applications begin to hang, background processes like WINWORD.EXE accumulate, and stability degrades under load—not because of application logic, but because Interop was built for desktop automation rather than server-side workloads. Bui