Deep DI-ving: how Angular’s DI system defeated a monolith

Abstract

The project had dozens of customizations for each client, and became an unmaintainable behemoth that held the entire team back. Breaking everything apart seemed impossible.

But Angular has always had a solution: its advanced and flexible dependency injection system. We took a deep look into it, and with a little ingenuity we started to separate the customizations from the core, and create a deliver workflow that eased everyone’s job. Environment providers, element providers, even the good old module providers: understanding the injector hierarchical system has been paramount to create a usable, flexible and powerful customization framework.