When deploying a Node.js application, if the NODE_ENV environment variable hasn’t been set to production, you may see the following warning:
Skip Pruning Because NODE_ENV is Not ‘Production’
This occurs because the NODE_ENV variable isn’t set to production by default during application creation.
To resolve or prevent this issue, manually add the NODE_ENV environment variable when adding your application or in your application’s Settings. If you add the environment variable in Settings after the application has been created, redeploy it from Deployments > Details.