Senior Software Engineer

Sandi Crowther Recruitment; South Africa; On-site; ZAR 700,000 - 1,100,000; Full time

Job summary

Sandi Crowther Recruitment is seeking an experienced embedded firmware engineer to design, develop and maintain C/C++ firmware for ARM Cortex‑M based devices. You will work with hardware and software teams, optimize power and security, and ensure reliable field deployments.

The role requires 8+ years of hands-on embedded development, RTOS experience (FreeRTOS), GSM/LTE modules, and strong debugging skills. This is a hands-on senior position with mentoring responsibilities.

Qualifications

• Minimum 8 years of embedded firmware / software development experience.
• Strong C and C++ skills, preferably with ARM Cortex-M microcontrollers.
• Experience with RTOS environments such as FreeRTOS or bare-metal development.
• Knowledge of GSM / LTE modules, AT commands and wireless communications.
• Understanding of UART, SPI, I2C, ADC, GPIO and DMA peripherals.
• Experience with Git, debugging tools, build systems and software testing.
• Proven ability to develop reliable, production-ready firmware for deployed devices.
• Strong analytical, problem-solving and communication skills.

Responsibilities

• Design, develop and maintain embedded firmware in C / C++ for microcontroller-based devices.
• Develop and optimise communication drivers, protocols and interfaces for cellular connectivity and embedded peripherals.
• Ensure firmware meets reliability, security and power-efficiency requirements.
• Collaborate with hardware and software teams on product development, integration, testing and improvements.
• Implement diagnostics, error handling and recovery mechanisms.
• Contribute to firmware architecture, coding standards, code reviews and technical documentation.
• Conduct software testing, support production processes and troubleshoot complex field issues.
• Keep up to date with cellular technologies, embedded security and relevant regulatory requirements.
• Provide technical guidance to junior engineers and improve development processes.

Skills

C/C++ programming

ARM Cortex-M

RTOS (FreeRTOS)

GSM / LTE modules

AT commands

UART / SPI / I2C / DMA

Git

Debugging & testing

Code reviews

Security awareness

Education

Relevant degree or equivalent practical experience

Tools

Git

Build systems

Debugging tools

Job description

Responsibilities:

• Design, develop and maintain embedded firmware in C / C++ for microcontroller-based devices
• Develop and optimise communication drivers, protocols and interfaces for cellular connectivity and embedded peripherals
• Ensure firmware meets reliability, security and power-efficiency requirements
• Collaborate with hardware and software teams on product development, integration, testing and improvements
• Implement diagnostics, error handling and recovery mechanisms
• Contribute to firmware architecture, coding standards, code reviews and technical documentation
• Conduct software testing, support production processes and troubleshoot complex field issues
• Keep up to date with cellular technologies, embedded security and relevant regulatory requirements
• Provide technical guidance to junior engineers and improve development processes

Requirements:

• Minimum 8 years' embedded firmware / software development experience
• Strong C and C++ skills, preferably with ARM Cortex-M or similar microcontrollers
• Experience with RTOS environments such as FreeRTOS or bare-metal development
• Knowledge of GSM / LTE modules, AT commands and wireless communications
• Understanding of embedded peripherals and interfaces, including UART, SPI, I2C, ADC, GPIO and DMA
• Experience with Git, debugging tools, build systems and software testing
• Proven ability to develop reliable, production-ready firmware for deployed devices
• Strong analytical, problem-solving and communication skills
• Relevant degree or equivalent practical experience

Advantageous:

• Experience in security, alarm systems, IoT, telemetry or industrial communications
• Knowledge of alarm signalling protocols, such as Contact ID
• Experience with OTA firmware updates, device management or low-power design
• Exposure to hardware development, PCB testing and ICASA compliance requirements
• Python scripting for test automation
• Previous technical leadership or mentoring experience

If you are passionate about embedded technology and enjoy tackling complex engineering challenges, this is an excellent opportunity to contribute to the development of innovative, reliable products.