Looking for a smart pH/EC meter PCBA designer

I am looking for an electronic technician/engineer who has hands-on experience building a smart pH meter to review, revise existing pH meter design. The pH meter contains 2 pH sensors, 1 EC sensor, and a high resolution display to display data and graphics. The product will send the pH/EC data to a smart phone app, which will display additional information. The app has been already designed. The PCB has been designed but may need revision QUESTIONS - Which pH or EC instruments have you built, and can you show or give references? - How would you deal with input leakage and noise in a high-impedance pH circuit? - How do they approach EC excitation and temperature compensation? - Can you review and revise an existing PCB (not just design from scratch)? Candidates with AI supported responses are automatic eliminated from the project.