Python-Based Custom Project Management System

I am in need of a proficient Python developer to build a custom project management system with a modern and sleek user interface. The ideal candidate for this job will have experience in web development, specifically Python and should be familiar with task management systems.

The system should have the following features:

- Task Management: This feature should allow users to create and assign tasks to team members and monitor progress.

- Team Collaboration: Users should be able to communicate effectively amongst themselves. This feature should enable tasks discussions, updates and feedback sharing.

- Document Sharing: This feature needs to enable users to share relevant documents seamlessly.

- Chat Functionality: A real-time chat feature for instant communication is also essential.

This system should cater to project managers, team members, and clients. Please ensure that the user interface is smooth and easy to navigate. Experience designing sleek user interfaces is preferred.

Your comprehensive understanding of the end users - Project Managers, Team Members, and Clients is crucial to the successful completion of this project. Apply if you have relevant skills and experience, and are ready for a challenge.