How can we setup an auto-backup job before every deployment

I have setup a cron Job, which is taking backup every night. It is working fine, but, i need to setup a job or script, which take the DB backup before every deployment.

As i have the Drupal Installed on the Platform SH Project. I can use Drush Command to take the backup. But Unfortunately, It can only be executed in Deploy Hooks and i can use that command only after deployment in, Which is useless.

Can anybody tell me any way to do it.
Or, if anybody can tell me how can i run command on Application root directory from “” file before deploy Hooks.

Thank you very much