Senior Embedded Software Engineer

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£65-80k / Hybrid - London

IONATE is a deep tech 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

Development

• Develop embedded software for grid-connected inverters.
• Design and implement real-time firmware from scratch for ARM Cortex-M microcontrollers; manage memory, peripherals, interrupts, and debug low-level issues
• Develop bare-metal and RTOS-based applications; reason about latency budgets, interrupt priorities, and timing edge cases in real-world deployments.
• Implement real-time platforms where to deploy control algorithms and closed-loop firmware that operate within hard timing constraints and safety requirements for grid-connected applications.
• Bring up new hardware platforms: configure peripherals, integrate sensors and actuators, validate functionality, and document the integration process.
• Troubleshoot firmware-hardware faults in test rigs and in the field; reproduce issues, analyse logs, and deliver robust fixes without disrupting future deployed systems.

Quality and Collaboration

• Work closely with hardware engineers, power electronics specialists, control engineers, and systems teams to define interfaces, timing budgets, and validation strategies.
• Participate actively in code reviews, design discussions, technical analyses and help raise the standard of the codebase.
• Contribute to safety and quality processes: able to identify regulatory standard compliance and ensure firmware aligns accordingly, maintain traceability, and document design decisions and test evidence.
• Create and maintain technical documentation including requirements, design specifications, test reports, and architecture notes.
• Work within clear timescales to deliver projects on time with ambitious product goals.

Requirements

What you will need

• A degree in electronics, embedded systems, software engineering, or related discipline, with demonstrated industrial experience.
• You will have 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.
• Demonstrable experience of working on embedded software projects using C/C++.
• Mastery of C language 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.
• A firm grasp 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 with 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 and USB.
• Ability to read PCB schematics and datasheets; experience testing/debugging PCBs.
• Previously set up or maintained CI/CD for embedded code, written unit tests for firmware, or used static analysis tools to catch defects early.
• Knowledge of digital closed-loop control applications.
• You have written or reviewed firmware against safety standards.

Benefits

• Employee Option Plan: You get equity in IONATE, so as we succeed so do you.
• Private Medical & Dental Insurance: From day one, we…