twelve-factor-processes

To audit stateless processes, review the application's process model to detect local state persistence, sticky sessions, and improper filesystem usage, then generate a remediation plan to migrate durable data to external datastores.

Sticky sessions bind user requests to specific processes using in-memory state, violating stateless architecture by preventing horizontal scalability and requiring migration to external shared datastores for session persistence.

Migrate local filesystem state to external datastores by identifying improper disk usage within your processes, extracting that durable data, and delegating persistence to external services to ensure scalable, non-shared processes.

Stateless processes are needed when applications require horizontal scalability and resilience, ensuring that any process can be replaced or scaled without losing critical in-memory or local filesystem state during architecture reviews.

Document Twelve-Factor compliance by auditing the application process model, verifying no durable state is stored locally or in-memory, and recording the migration steps taken to delegate persistence to external services.

Storing state on the local filesystem breaks scalability because subsequent requests may route to different processes that lack access to that data, requiring external datastores to maintain consistent shared state across non-shared processes.