Developing a Customized OS for Rasberry Pi -- 2

We are developing a diagnostic unit. We want to develop it as a dedicated launch on power app for Raspberry Pi any ESP or Arduino in between. The data inputs would include ECG, BP and Air Pressure from modules. It would also include a touchscreen GUI. We are looking for a freelancer with the expertise required to develop it for Pi. We basically need someone to translate our complete C++ code for Pi to run the sensor there with an UI as per our design. Further details will be provided only after signing of a Non-Disclosure Agreement.