We are looking for seasoned embedded developer who know ARM Processors really well, understands development for RTOS and has experience in VOIP. Note! Our client is very strict about the requirement above. Please, offer only candidates who have all the three skills available. The device is based on the STM32F7 MCU with external SDRAM. Internet connectivity is achieved using LTE, WiFi, and Ethernet. Terminal device connectivity is done with subGHz radios using Everon proprietary protocol. The device runs on top of FreeRTOS, and the TCP/IP stack used is LWIP. The codebase is written in C. We need help refactoring the code to enable us to add more features and provide more resilience. We plan to add MQTT connectivity and a VOIP client. Audio capabilities are provided by a DSP chip that handles the AEC and provides an I2S stream to the MCU. We require a senior developer capable of providing vision for the refactoring process, preferably with experience in VOIP through LTE or at least experience in streaming time-critical data through LTE.