The Twelve-Factor App (2025)

The twelve-factor app is a methodology for building software-as-a-service applications that emphasizes automation, portability, cloud compatibility, and minimal divergence between development and production environments. Developed from experience managing hundreds of apps on the Heroku platform, the methodology comprises twelve principles covering areas like codebase management, dependency declaration, configuration handling, and process management. The approach can be applied to applications written in any programming language and is intended as a guide for developers and operations engineers building scalable, maintainable cloud-based services.