Comprehensive ERP System Development

I'm seeking a skilled developer to build a robust web-based ERP system with the following modules:

- Inventory Management
- Customer Relationship Management (CRM)
- Human Resources
- Invoicing

Ideal candidates should have:

- Expertise in both frontend and backend development.
- Proficiency in PostgreSQL.
- Experience with ERP systems and their various modules.
- Strong understanding of web application architecture and design.

Please provide examples of similar projects you've completed.