Firmware Engineer for BMS Development

I am looking for a firmware engineer, having an experience in BMS Firmware Development. He should have the following experience:
1. Firmware development of STM32, AVR MCU's.
2. Firmware development of CAN Protocol.
3. RTOS Development
4. SOC, SOH

Note:
1. Please share your past experience in BMS Firmware Development.
2. Please share your estimate cost and timeline.