Pre-deployment.
CODE
Changes tested somewhere that is not production No debug mode enabled No credentials in code No commented-out experiments left in
DEPENDENCIES
Requirements file current New dependencies pinned Installed in the target environment
CONFIGURATION
Required environment variables set on the server Application fails clearly at startup if any is missing
DATABASE
Any schema change prepared and applied in order A backup taken before applying it
DEPLOYMENT
Files deployed, excluding environment and secrets Dependencies installed before restart Application restarted Log checked for a clean startup
VERIFICATION
Application responds Key functions work, not only the homepage Scheduled tasks still function Mail sending still works
ROLLBACK
A way to return to the previous version, known before starting
TIMING
Not during a busy period.
