The Twelve-Factor App

The Twelve-Factor App is a methodology for building modern software-as-a-service applications. It provides a set of best practices designed to create scalable and maintainable apps that are suitable for deployment on modern cloud platforms. Following these principles helps to minimize divergence between development and production, enabling continuous deployment for maximum agility.

The methodology promotes:

• Using declarative formats for setup automation to minimize onboarding time for new developers.
• Creating a clean contract with the operating system for maximum portability between execution environments.
• Enabling apps to scale up without significant changes to tooling, architecture, or development practices.
• Strictly separating build and run stages and treating backing services as attached resources.

This approach is language-agnostic and can be applied to any app that uses backing services like databases, queues, or caches.