Senior / Principal Firmware Engineer

Endurance Energy • Seattle, WA

22h • Onsite

About The Position

Endurance is developing modular seafloor geothermal power plants that harness the vast thermal energy beneath the ocean floor to provide gigawatts of clean, reliable energy. We're addressing the critical power bottleneck facing AI infrastructure development while creating a path toward energy independence and decarbonization across the globe.
Backed by premier venture capital firms including First Round Capital and Point72 Ventures, our exceptional founding team includes veterans from SpaceX, Neuralink, Robinhood, and Helion with specialized expertise in complex thermal and fluid systems.
We're seeking a talented Firmware Engineer to join our team at our headquarters in Seattle, where you'll help design and develop the core power cycle for our revolutionary seafloor generators.

As a Senior / Principal Firmware Engineer at Endurance, you'll work with our founding firmware and electrical team to own the brains of the world's first subsea geothermal power plants. Starting from a blank sheet, you will be responsible for rapidly architecting, building, and testing embedded systems across our platform. This position requires not only technical experience, but also the flexibility, creativity, and entrepreneurial mindset essential to an early-stage startup.

Requirements

• Bachelor’s degree in electrical engineering, computer engineering, computer science, mathematics, or related STEM field; OR 5+ years of experience in writing firmware for microcontrollers or low-level software in lieu of a degree
• 3+ years of experience in embedded firmware development
• Proficiency in C/C++, bare-metal, RTOS, debugging with GDB/JTAG, Python scripting for tools/tests, version-control and code-review
• Strong grasp of computer architecture, including memory/peripheral maps, DMA, and timing analysis
• Familiarity with common MCU peripherals (SPI, I²C, CAN, Ethernet, UART, ADC/PWM)
• Comfort working around 800 V+, Megawatt-class equipment
• Familiarity with oscilloscopes, logic analyzers, and other common electrical lab equipment
• Willing to work hands-on and occasionally off-hours to meet mission/test windows

Nice To Haves

• Experience writing firmware for power converters, motor drives, high-voltage battery packs, and battery chargers
• Experience creating fault-tolerant, distributed, or deterministic control systems with graceful degradation and watchdog recovery
• Experience implementing self-test, diagnostics, FDIR/FMEA, redundant sensing/actuation, and over-the-air update mechanisms

Responsibilities

• Lead the embedded system design of our novel subsea geothermal power plants
• Develop early communication systems between our deployed hardware and engineers on land
• Support bring-up of the high power electrical systems your firmware integrates with
• Validate and debug your own work and the broader system
• Be hands on in the lab, including supporting hardware assembly as needed
• Support deployments of test coupons, prototypes, and production hardware to the ocean floor
• Support business development activities including supplier meetings, technical presentations, and customer interactions

Benefits

• Global Fieldwork: Travel to fascinating deployment sites along oceanic ridges in locations like the Pacific Northwest, Hawaii, Iceland, Japan, New Zealand, and the Azores
• Hands-on Experience: Participate in sea trials and deployment operations in partnership with leading oceanographic institutions
• Cutting-Edge Development: Work with technology that spans high-power electronics, marine systems, and clean energy
• Impact-Driven Work: Help solve one of the world's most pressing challenges - clean, reliable power generation
• Competitive Compensation: Comprehensive salary and equity packages
• Benefits: Vision, Dental, Health insurance coverage
• Dive Certification: Company-sponsored recreational dive certification
• PTO: Unlimited (with advanced notice)

What This Job Offers

• Job Type: Full-time
• Career Level: Senior