Mechanical Engineer Needed to Turn Product Concept Into CAD

We have a physical product concept that needs to be developed into a proper mechanical design.
The basic idea is already defined, but the current design needs engineering work around dimensions, component interfaces, materials, fasteners, and manufacturability.
The selected engineer will develop the 3D CAD model, build the assembly, resolve mechanical interfaces, and prepare the files needed for prototyping.
SolidWorks or Fusion 360 experience is preferred. We need someone who understands the engineering behind a product, not just someone who can create attractive CAD models.