POS middleware software developer for self-check-out kiosk software

We develop a new series of self-check-out and pre-order kiosks for retail markets and restaurant application. Therefore we look for a very experienced developer or agency with vast experience in the development of Point-of-Sales solution, like WallacePOS, or Unicenta. However most important is skills with Linux, Java and Container/Dockers as the main target of this job is the development of an ultra-fast and ultra-secure solution running as middleware on the Kiosk hardware itself, while doing all sync work with the server backend. It is OS as docker/container, Database connection using MongoDB or ittia. Middleware must communicate with the drivers of all build in modules like printer, scanner, nfc, btle, Payment gateways. One device provides drivers only in JavaPOS!. UI/UX runs on seperate device under Android. In addition experience with self-service kiosk development, partly embedded software layers to monitor and control peripherals drivers, payment gateways, following PCI 3.x and EMV.x standards would be of help. We are not interested in you, if you have not done at least in each section one successfull projects before. This is not a try-and-error approach. First step would be reading our project document and provide an RFI.