The Twelve Factors

The factors for Twelve-Factor Apps are as follows:

1. Code base. Store the code in a single repo and differentiate only by configuration.
2. Dependencies. Declare them explicitly and clearly.
3. Config. Config through the environment.
4. Backing services. Any backing service should be treated as an attached resource.
5. Build, release, run. Differentiate between build and run states.
6. Processes. Execute the app as a stateless process.
7. Port binding. Expose services through ports.
8. Concurrency. Set up the services as processes.
9. Disposability. Fast start and graceful shutdown.
10. Dev/prod parity. All environments should be as similar as possible.
11. Logs. Send logs to event streams.
12. Admin processes. Run one-off admin processes independently.

The factors can be grouped around different concepts:

• Code base, Build, release, run, and Dev/prod parity work around the idea of generating a single application...