Twelve-Factor App
Noun · Development
Definitions
A methodology of twelve principles for building modern cloud-native applications, published by Heroku co-founder Adam Wiggins in 2011. Key factors: store config in environment variables, treat backing services as attached resources, use stateless processes, separate build/run stages, and achieve dev/prod parity. Still relevant 15 years later.
In plain English: Twelve rules for building applications that work well in the cloud, covering things like configuration, logging, and statelessness.
Example: "The app violates factor #3 (config) by hardcoding the database URL and factor #6 (processes) by storing sessions in local memory."