Identify where the WSGI server captures standard error and whether the hosting panel exposes that log. Decide who can read logs and how long they should be retained.

1. Configure Python logging early in application startup, before code first accesses the Flask logger. Choose the destination supported by the hosting runtime.

2. Use a production log level and a format containing a timestamp, severity and a useful request or release identifier.

3. Keep passwords, authorization headers, cookies and full request bodies out of routine logs. Redact sensitive values when an exception includes external service details.

4. Configure log rotation or the managed platform’s retention controls. Ensure file-based logging uses a writable private directory and handles multiple processes appropriately.

5. Trigger a harmless controlled application error in staging, then check that the operator receives the diagnostic information while the visitor receives a generic error response.

A useful private log entry can identify the failing request and release without storing the submitted form or an authorization header.

2026-10-05T09:15:00Z ERROR request_id=test-42 release=release-18 operation=save_profile outcome=database_unavailable

This is an illustrative record, not a required logging format. Keep the request ID consistent with the web-server or application diagnostic path. Capture the detailed exception privately through the approved handler, after checking that its message does not contain a connection password or sensitive request values.

Trigger a controlled staging failure and confirm one useful entry appears in the expected destination. The visitor should receive the application's generic error response. If the same event appears several times, inspect handler attachment and logger propagation before raising the log level or retaining more duplicate data.

Match the request time with the application log and WSGI server log. Confirm the intended handler records an error once instead of creating multiple duplicate copies through logger propagation.

If no log appears, check the runtime’s stderr capture, handler setup and file ownership. Enabling the interactive debugger on a public site is not an appropriate substitute.

• Deploying a Flask application factory on WSGI hosting
• Setting retention limits for application logs
• Recording useful API error details without secrets
• Configuring trusted proxy headers for Flask

• Flask logging
• Python logging