Merging PDFs sounds simple — until you try to do it in a real-world .NET application running on a server. Without a local desktop environment, approaches that rely on Microsoft Office quickly fall apart: licensing restrictions, deployment headaches, and poor performance under load make it a poor fit for server-side .NET applications. That's usually the point where developers start looking for alternatives. The good news is you don't need Office at all. Several dedicated .NET libraries handle PDF merging cleanly, without any Office dependency — and they give you far more control over the output. In this guide, we'll walk through the practical side of merging PDFs in .NET: a working setup, the issues developers most commonly run into, and how to fix them. A Clean Way to Merge PDFs in .NET When merging PDFs in a .NET application—especially on the server—the biggest challenge isn't writing the code itself.…