What common mistakes are made when setting up application deployment?

Common deployment setup errors include:

• Lack of automation or insufficient automation, leading to manual deployment errors.
• Mismanagement of configurations, such as storing secrets in code or not separating configs for different environments.
• Ignoring monitoring and logging, which makes troubleshooting difficult post-deployment.
• Insufficient testing in a production-like environment, causing bugs to appear only in production.
• Lack of rollback mechanisms, complicating recovery from failed deployments.

Example: forgetting to update environment variables for database connection during deployment can prevent the app from starting.