fix cronjob scaping and posting duplicate entries

I am looking for a skilled freelancer who can fix the issue with my custom-built system's cronjob. The cronjob is currently running on a custom-built system and is written in PHP. The issue at hand is related to posting duplicate entries.

Skills/Experience Required:
- Strong experience with custom-built systems
-database programming
- Proficiency in PHP programming
- Knowledge of cronjob management and troubleshooting
- Ability to identify and fix issues related to posting duplicate entries