Project Management SaaS Development

I need a skilled developer to create a SaaS platform focused on project management. The primary function of this platform is to facilitate team collaboration, with document sharing as an essential tool.

Key requirements:
- Task tracking
- Team collaboration
- Resource planning
- Document sharing

Ideal skills and experience:
- Proficiency in SaaS development
- Strong background in project management tools
- Experience with collaboration features, especially document sharing
- Knowledge of UI/UX design for a seamless user experience

Please provide examples of similar projects you've completed and your approach to ensuring robust team collaboration features.