What is The Twelve Factor App? The Twelve Factor App a methodology for building modern, scalable, maintainable Software-as-a-Service (SaaS) apps. The Twelve Factor App is a set of principles that describes a way of making software that, when followed, enables companies to create code that can be released reliably, scaled quickly, and maintained in a consistent and predictable manner.
Why Do You Need The Twelve Factor App? In the modern era, software is commonly provided as a service: so-called Web Applications or Software as a Service.