Firmware Engineer – IoT

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AirEx is looking for a talented Firmware Engineer with experience in the IoT space, to join our mission to tackle Fuel Poverty and Climate Change.



AirEx is a rapidly growing energy efficiency start-up, designing and manufacturing the UK’s first smart air brick technology, helping householders reduce their energy bills without compromising air quality. We are looking to hire an exceptional Firmware Engineer to contribute to the company’s business mission by leading and executing Airex’s firmware development activities.


Climate change is the biggest challenge of our lifetime and this is an exciting opportunity to have an impact on this problem in one of the fastest growing areas of cleantech. AirEx’s mission is to lift millions of households out of fuel poverty and reduce the UK’s carbon emission with an affordable solution for the mass market. With our recent Ofgem approval under the ECO (Energy Company Obligation) scheme, AirEx is now entering an exciting new phase with ever increasing demand from social landlords, energy companies and retrofit installers. Your role will therefore be absolutely crucial in contributing to the company’s growth through product development.



  • Collaborating with the CTO in creating the Company’s technical strategic planning to achieve business goals by identifying and prioritising development initiatives
  • Managing and building a firmware development process
  • Firmware development and maintenance on our hub, smart air bricks, sensors, and any new products being developed in-house
  • Perform debugging and testing for hardware/firmware to prove that we meet product requirements
  • Collaborating with external contractors when needed
  • Working with the team to ensure various design decisions around firmware, hardware, system architecture, and customer requests are implemented smoothly from the firmware perspective


  • Significant experience with embedded development in C/C++
  • Experience with developing medium complexity applications on ESP32 and ARM devices
  • Configuring embedded systems to minimise energy consumption and maximise battery life
  • Building secure wireless communications with standard encryption methods
  • Understanding of RF communication protocols and modulations such as LoRaWan, WiFi, and NB-IoT.
  • Experience with delivering over the air updates and boot loaders
  • Working with an embedded RTOS in a low power system
  • Experience with AWS IoT Core & MQTT is a plus
  • Familiar with agile development and associated tools



The ideal Candidate will be passionate about the cleantech and IoT, eager to work in a start-up and happy to roll up their sleeves and take on anything that comes their way.

  • You are ambitious, resilient, and results-driven, with a “Getting-Things-Done” mindset
  • You are a motivated self-starter, proactive and hands-on, keen to work to fix issues quickly
  • You are articulate both verbally and in writing
  • You are keen to grow and develop with the company and can take on greater responsibility as the business grows
  • You are naturally collaborative in your approach and able to inspire others
  • You have a passion for start-ups and are interested in cleantech / IoT
  • You feel you can successfully navigate the evolutionary pressures of a start-up



AirEx is a spin-out company from Sustainable Ventures; an incubator/VC that works with investors, entrepreneurial managers, corporate partners, and public sector bodies to originate, build, grow, and exit sustainable businesses. SV’s portfolio companies benefit from the on-going support of the Sustainable Ventures management team who have already established 14 low carbon ventures, attracting over £250m in equity commitments. Furthermore, AirEx is located at Europe’s largest sustainable start-up hub, Sustainable Workspaces; a shared office space with over 600 members across 50+ cleantech start-ups.



  • £40k – £55k (depending on experience)
  • Becoming part of a rapidly growing start-up operating in an exciting sector
  • The opportunity to work on a product that will improve the lives of millions of people
  • Managing your own work and enjoying plenty of freedom as part of a small, tight-knit team
  • Flexible working: combination of home-based/office-based work (London HQ)
  • An exciting, problem-solving, and dynamic atmosphere, a flexible and fun work environment filled with passionate and extremely capable people


At AirEx we embrace diversity. To excel in our interdisciplinary work we need a team that can view problems from many perspectives. We are committed to hiring the best talents regardless of age, disability, gender, marital status, nationality, race, religion, sexual orientation, or social background.


Please get in touch with us by email at


Salary: 40k to 55k GBP