Senior Embedded Software Engineer (Hiring Immediately) in London

£65-80k / Hybrid - London

IONATE is a deep technology scale-up building the hardware and software backbone for smart grids. Our mission is to transform power systems – from grids and microgrids to renewables and data centres – unlocking the massive potential in this under-innovated sector that touches every aspect of our modern lives.

We are looking for a Senior Embedded Software Engineer to join our team. You'll work with our hardware and systems team to design and implement production C/C++ firmware, spanning embedded software architecture, control algorithm implementation, hardware-firmware integration, and active participation in verification, validation, and live product testing. You will bring a practical, evidence-based approach to engineering decisions and contribute to advancing our HIT technology for grid-connected systems.

What you will do:

• Develop embedded software for grid-connected Power Electronics Systems.
• Design and implement real-time firmware from scratch for ARM Cortex-M microcontrollers, including memory management, peripherals configuration, interrupts handling, and low-level debugging.
• Develop both bare-metal and RTOS-based embedded applications.
• Implement real-time platforms for deploying control algorithms operating under hard timing constraints and strict safety requirements for grid-connected applications.
• Bring up new hardware platforms by integrating sensors and actuators, validating system functionality, and documenting the integration process.
• Troubleshoot firmware–hardware issues in laboratory test rigs and field deployment by reproducing faults, analysing logs, identifying root causes and delivering robust corrective solutions.

Quality and Collaboration

• Work closely with hardware engineers, power electronics specialists, control engineers, and systems teams to define interfaces, establish timing budgets, and develop validation strategies.
• Participate actively in code reviews, design discussions, and technical analyses, contributing to continuous improvement and elevating overall code quality.
• Contribute to safety and quality processes by identifying applicable regulatory standards, ensuring firmware compliance, maintaining requirements traceability, and documenting design decisions and test evidence.
• Create and maintain technical documentation including requirements specifications, architecture designs, test plans, and validation reports.
• Deliver high-quality results within defined timeframe, supporting ambitious product objectives and meeting project milestones.

What you will need:

• A degree in computer science, electronics, embedded systems, or related discipline.
• Industrial experience building real-time embedded systems – developing, shipping and supporting firmware in complex products, from prototype through to deployment.
• Solid understanding of real-time and deterministic embedded software design principles or best practice.
• Demonstrable experience of working on embedded software projects using C/C++.
• Solid understanding of C and its underlying implementation cost function.
• You can write efficient, predictable and maintainable code under strict constraints.
• Proven experience developing bare-metal and RTOS applications, managing interrupt priorities and latency budgets, and debugging race conditions and timing issues in deployed real-time systems.
• Solid understanding of interrupt handling, inter processor communications and synchronisation mechanisms.
• Good knowledge of performance optimisation techniques and hardware/software interaction.
• You can diagnose firmware–hardware faults using oscilloscopes, logic analysers, JTAG debuggers, and low-level inspection.
• Strong communication and written skills.
• Willingness to travel nationally and internationally for testing/commissioning when required.

It would be useful to have:

• Understanding of power electronics, grid interconnection, or motor control firmware.
• Demonstrable track record of developing for ARM-Cortex-M/R/A processors.
• Proficiency in a scripting language (e.g. Python, TCL, Bash) for test automation, tooling or data analysis.
• Experience architecting real-time Linux drivers or kernel modules; you understand device trees, OS-level interrupt handling, and the trade-offs between RTOS and embedded Linux.
• Working knowledge of MPSoC platforms (Xilinx Zynq); you have experience knowledge of FPGA languages such as VHDL or Verilog.
• Experience with communication protocols such as UART, SPI, I2C, Ethernet.