WhatsApp API Integration

I'm looking for a skilled developer to integrate the WhatsApp API with the following functionalities:

- Sending and receiving messages
- Automated replies
- User authentication

Messaging formats will primarily be text messages and documents.

Ideal skills and experience:
- Proven experience with WhatsApp API
- Proficient in setting up automated replies and user authentication
- Familiarity with text and document messaging formats
- Experience in integrating APIs with various systems (preferably CRM or e-commerce)

Please provide examples of similar work done.