What does the 12-factor app principle imply for deployment?

What does the 12-factor app principle imply for deployment?

• A. Build scalable, portable, stateless apps that can be deployed anywhere
• B. Deploy monoliths only
• C. Build apps that require specific environments
• D. Focus on local statefulness for performance

Answer: (A)

The main idea being tested is that a 12-factor approach drives deployment flexibility by making apps scalable, portable, and stateless so they can run anywhere. In practice, this means building processes that start quickly, run independently, and don’t rely on local memory or disk to keep lasting state. Configuration is kept separate from code and supplied via environment variables, while any persistent data lives in backing services (databases, queues, etc.) external to the app process. With these traits, you can deploy the same app across different environments and platforms, scale out by adding more stateless instances, and replace or move services without breaking the app. Why this matters for deployment: stateless processes can be started, stopped, and replaced easily, which is essential for auto-scaling, continuous deployment, and cloud portability. Externalized config and external backing services remove environment-specific dependencies from the code, making deployments consistent from local to production. Other options don’t fit because they imply patterns the 12-factor approach avoids: monoliths hinder independent scaling and portability; app environments tied to specific setups defeat portability; and relying on local state undermines disposability and horizontal scaling.

The main idea being tested is that a 12-factor approach drives deployment flexibility by making apps scalable, portable, and stateless so they can run anywhere. In practice, this means building processes that start quickly, run independently, and don’t rely on local memory or disk to keep lasting state. Configuration is kept separate from code and supplied via environment variables, while any persistent data lives in backing services (databases, queues, etc.) external to the app process. With these traits, you can deploy the same app across different environments and platforms, scale out by adding more stateless instances, and replace or move services without breaking the app.

Why this matters for deployment: stateless processes can be started, stopped, and replaced easily, which is essential for auto-scaling, continuous deployment, and cloud portability. Externalized config and external backing services remove environment-specific dependencies from the code, making deployments consistent from local to production.

Other options don’t fit because they imply patterns the 12-factor approach avoids: monoliths hinder independent scaling and portability; app environments tied to specific setups defeat portability; and relying on local state undermines disposability and horizontal scaling.