Need Arduino firmware expert

I need someone experience in Arduino programming. The job is to create the firmware for an Arduino Nano with multiple simple sensors (LEDs, temperature, buttons, EEPROM, RTC, etc...). You need to be able to code object-oriented (a class for each sensor) and know how to have multiple process running (using timers or interrupts, no delays or halting the MCU). It can also help if you know a lot of open-source libraries that can be used/adapted. Detailed specification will be provided to selected candidates.