Asterisk & FreePBX Call Center CRM Expert

I'm in search of a seasoned Asterisk & FreePBX developer to create a comprehensive call center CRM. This web-based interface system should prioritize Direct Inward Dialing and incorporate essential call handling features such as Call Barge, Call Whisper, and Call Mute. Additional functionalities should encompass Call Queues, Call Transfer, Call Pause, Lead Upload, Recording, and Call Scheduling.

Key Features:
- Direct Inward Dialing as the top priority
- Web-based interface for user accessibility
- Critical call handling features: Call Barge, Call Whisper, Call Mute
- Other functionalities: Call Queues, Call Transfer, Call Pause, Lead Upload, Recording, Call Scheduling

Ideal candidates should have:
- Extensive experience with Asterisk & FreePBX
- Strong web development skills
- Prior experience in building call center CRM systems
- Proficient understanding of call center operations
- Ability to provide ongoing support and enhancements for a long term collaboration.