RPi Kernel Development

We are looking for a Linux or Raspberry Pi Operating System expert. We need a RPi OS to be done for us that should fast boot and run any QT application. We have something in place that we used for many years but the boot time is slow (around 15 seconds). We have found this which we would like to use, but may need optimising a little to give us the right IMG file and guidance on where to put our QT application file on the micro-SD card to run it correctly.
https://furkantokac.com/rpi3-fast-boot-less-than-2-seconds/

For more information or questions please get in touch. Thank you.