Web app for simple 3D modeling similar to https://www.tinkercad.com

I am looking for a skilled developer to create a web app for professional use that allows for simple 3D modeling. The level of complexity required for the modeling is moderate. The ideal candidate should have experience in web development and 3D modeling.

Key requirements for the web app include:

- a list of basic 3D shape library for users to choose from
- use mouse to place, scale, rotate a 3D object with respect to another one on canvas
- use Boolean operation in between basic shapes to create more complex 3D objects
- Import/Export functionality: The ability to import existing 3D models into the app and export the created models in various file formats.

Additional details:

- The web app will be used primarily for the modeling of radiation shielding structure or radiation detectors.
- The app should have a user-friendly interface that allows for easy manipulation of 3D objects using mouse and keyboard.
- Online collaboration features are preferred but can be enabled at a later stage.

If you have the skills and experience in web development and 3D modeling, please submit your proposal outlining your relevant experience and previous projects.