Customise the Flexisip call routing

Title: Customise the Flexisip call routing

Description:
I am looking for a freelancer to customise the call transfer feature in the Flexisip call routing system.

Specific Requirements:
- The call transfer feature needs to be tailored to my specific requirements
- I have specific preferences and expectations for the call transfer feature
- The routing should handle the destination call from the database registry.
- The routing will be upon the selection of IVR menu
- The IVR menu played is depend on the called number.

Preferred Method of Implementation:
- The call transfer feature should be implemented through the backend of the system

Ideal Skills and Experience:
- Strong knowledge and experience with Flexisip call routing system
- Expertise in customising call transfer feature
- Proficiency in backend development and integration

Note: Please provide examples of previous work related to call routing customization.