The Twelve-Factor App: Codebase, Dependencies, and Config

Dev-Prod Divergence

Development and production environments often diverge, leading to significant challenges in application deployment. Allen Underwood emphasizes the importance of minimizing this divergence to enable continuous deployment and maintain agility. He notes, "If you've ever been in a situation where that is not the case, then you know how crazy it is to try and make your applications work when things have diverged too much." 1 This divergence often stems from differences in data and configuration, making it crucial to manage environment variables effectively 2.

   

Dependency Isolation

Isolating dependencies in .NET environments presents unique challenges, particularly with older frameworks. Michael Outlaw highlights the difficulty of ensuring all dependencies are correctly declared and isolated, especially with the Global Assembly Cache (GAC) complicating matters 3. He explains, "The GAC was trying to centralize that as one repository and make it all nice and simple. But then that became a real problem." 4 The evolution towards ASP.NET 5 aims to address these issues by simplifying dependency management and reducing reliance on shared libraries 5.