When you’re standing up a web app, developers are trying to build required functionality quickly and at a low cost: budgets are still tight, teams are small, and resources are thin. These teams often turn to open-source tools to add PDF viewing functionality, and these libraries work: they give you the basics with simple integration and zero cost.However, whether you’re a scrappy startup or an established organization building new functionality in a platform with a large existing user base, open-source libraries can become a bit of a monkey’s paw: they’ve granted your wish, but the pain comes later. In the case of document processing functionality, this pain comes in the form of integration hell, as you need to add more document capabilities one after another, and the capabilities and dependencies of all the open-source libraries you’ve integrated start to show some cracks. Maintenance grows, user experience suffers, and developers are gently resting their foreheads on the desk.