Can you explain the main principles underlying the architecture of the Twelve-Factor App?

The Twelve-Factor App architecture is a set of principles for developing modern cloud applications that ensure scalability and ease of maintenance. The main principles:

1. Codebase — one codebase tracked in version control, many deployments.
2. Dependencies — explicit declaration and isolation of dependencies.
3. Configuration — stored outside of code, for example, in environment variables.
4. Backing services — all external services (databases, queues) are attached as resources.
5. Build, release, run — clear separation of stages.
6. Processes — the app runs as one or more stateless processes.
7. Ports — the app exposes services via ports.
8. Concurrency — scaling by running multiple processes.
9. Disposability — processes do not maintain state, making them easy to restart.
10. Dev/prod parity — minimal differences between development and production.
11. Logs — the app does not manage logs but outputs them to stdout.
12. Admin processes — administrative tasks are run as one-off processes.

These principles help create applications that are easily scalable, updatable, and maintainable in a cloud environment.