Node-red app development on RPi for a control system

If you have the needed HW it will be a plus. Remote access of HW can be provided but not preferred as it takes much longer development time. We have multiple RPi modules interconnected as a single global system which will need to be programmed as an integrated system. The system will need to support several mathematical equations, algorithms, PID controls & sequential logic. Several modules have already been developed by us. The complete system specs will be shared with short-listed candidates and will need to have a fixed price/delivery quoted afterwards. Currently we need to get list of prospective candidates who can convince us about their talent, availability & ability to take up & successfully complete the job. FAT will have to be done remotely & then tech transfer to us, so future minor changes etc. can be handled by us. All the source code and supporting docs will need to be submitted & accepted by us before job completion is declared. Also, need you to hide the code (not just user login) from the user.
Currently need your detailed experience about relevant experience. The rates given are placeholders only - bid your best rates. Please DO NOT provide any unrelated details or info or a BOT response as that will be counted as a negative gesture & considered as ignoring instructions. No scope for on the job training, please. Write "Node-red" as first word of your response.