Senior IoT Engineer in London

Fuse Energy is a forward-thinking renewable energy startup on a mission to deliver a terawatt of renewable energy - fast. We're combining first-principles thinking with cutting-edge technology to build a radically better energy system. We raised $170M from top-tier investors including Multicoin, Balderton, Lakestar, Accel, Creandum, Lowercarbon, Ribbit, Box Group and strategic angels like Nico Rosberg, the Co-Founder of Solana and GPs behind Meta, Revolut, Spotify, Uber and more.

We’re creating a fully integrated energy company: from developing solar, wind and hydrogen projects to real-time power trading and distributed energy installations. By selling directly to consumers, we cut out the middleman, lower costs and pass on savings to customers.

But we’re not stopping there. We’re also building the Energy Network: a decentralised platform of smart devices that rewards users in Energy Dollars for electrifying their homes, shifting usage to off-peak hours, and helping balance the grid. This network strengthens grid stability - a critical foundation for scaling AI data centers and other energy-intensive industries.

We’re looking for a Senior IoT Engineer to help design, build, and scale the connected hardware powering the Energy Network. This is a hands-on role spanning embedded systems, networking, device security, and fleet connectivity — from prototype through to deployment. You’ll contribute to building resilient connectivity, secure provisioning, and robust telemetry across a growing fleet of distributed energy devices.

You’ll play an important role in shaping how our devices connect, communicate, and evolve securely at scale, working closely with firmware, hardware, and backend teams to deliver production-ready systems.

• Connectivity & Networking
  • Develop and maintain connectivity across Ethernet, Wi-Fi, Thread, Zigbee, and BLE.
  • Build and optimise secure, reliable device messaging using protocols such as MQTT, CoAP, HTTP, or WebSockets.
  • Support reliable device time synchronisation using NTP or PTP.
• Device Security & OTA Management
  • Contribute to secure boot flows, key and certificate provisioning, and hardware-backed device identity using TPMs or secure elements.
  • Help build and maintain signed firmware update pipelines, including OTA update and rollback mechanisms.
  • Support security best practices across the device lifecycle, including vulnerability management and secure provisioning.
• Edge & Cloud Integration
  • Integrate devices with cloud IoT platforms and backend services.
  • Define and improve telemetry, health monitoring, and observability for deployed devices.
  • Support reliable operation of connected devices in the field, including debugging fleet issues and improving resilience.
• Compliance & Testing
  • Support testing and validation for safety, EMC, radio, and related product requirements.
  • Help prepare test plans, certification artefacts, and validation documentation.
  • Work with manufacturing and cross-functional teams through engineering and production validation cycles.
• Cross-Functional Collaboration
  • Work closely with firmware, hardware, power electronics, mechanical, and software teams to deliver production-ready devices.
  • Contribute to design reviews, technical documentation, and interface specifications.
  • Share knowledge and contribute to engineering best practices across connectivity, embedded systems, and device security.

• Bachelor’s degree in Electrical Engineering, Computer Engineering, Computer Science, or equivalent practical experience.
• 5+ years of experience building connected embedded products, or strong relevant industry/project experience.
• Good proficiency in C/C++ for embedded systems, with experience working with RTOS environments such as Zephyr or FreeRTOS.
• Experience with Python for testing, tooling, or automation.
• Solid understanding of device connectivity and networking fundamentals, including IP networking and common transport/application protocols.
• Experience implementing or supporting secure device communications using TLS, certificates, or device provisioning workflows.
• Familiarity with firmware update systems, bootloaders, or CI/CD workflows for embedded software.
• Practical debugging experience using lab and software tools such as logic analysers, protocol analysers, network sniffers, or observability platforms.
• Strong problem-solving skills and the ability to work across hardware and software boundaries.

• Experience with low-power wireless technologies such as Thread, Zigbee, or BLE.
• Familiarity with cloud IoT services on AWS, Azure, or GCP.
• Exposure to secure boot, TPMs, secure elements, or hardware attestation.
• Experience with EMC/RF testing, antenna bring-up, or factory test processes.
• Awareness of relevant cybersecurity or privacy standards such as IEC 62443, ETSI EN 303 645, ISO 27001, or GDPR.
• Experience working on industrial, energy, or other distributed device deployments.

• Competitive salary and an equity sign-on bonus
• Biannual bonus scheme
• Fully expensed tech to match your needs
• Paid annual leave
• Breakfast and dinner allowance for office based employees