Google Cloud-Based Project Management App

I am looking for a competent developer to help me create a web-based application leveraging Google Cloud. This application will primarily serve for project management and file sharing.

Key Features:
- Task Management: The ability to assign, track, and manage tasks is integral to this project. The application should allow for the creation and management of team tasks efficiently.
- File Sharing and Collaboration: Users should be able to share files easily and collaborate on them in real time. This includes modification tracking and version control.
- Activity Tracking: It’s important for the system to track user activities and provide meaningful analytics.

Authentication:
- Users should be able to register and login using Email and Password, as well as leveraging Single Sign-On (SSO) capabilities.

Integrations:
- The application should offer Calendar Integration for effective scheduling and Email Integration for seamless communication within the platform.

Ideal freelancer for this job should have prior experience in developing similar applications and should be well versed with Google Cloud Platform, user authentication protocols, and third-party API integrations. Proficiency in full-stack development with a special emphasis on backend is a must. Understanding project management realities will be a definite plus.