Lightmatter is leading the revolution in AI data center infrastructure, enabling the next giant leaps in human progress. The company invented the world’s first 3D-stacked photonics engine, Passage™, capable of connecting thousands to millions of processors at the speed of light in extreme-scale data centers for the most advanced AI and HPC workloads. Lightmatter raised $400 million in its Series D round, reaching a valuation of $4.4 billion. We will continue to accelerate the development of data center photonics and grow every department at Lightmatter! If you're passionate about tackling complex challenges, making an impact, and being an expert in your craft, join our team of brilliant scientists, engineers, and accomplished industry leaders. Lightmatter is (re)inventing the future of computing with light! About the Role At Lightmatter, we build photonic interconnect chips designed for large-scale AI compute clusters. As an Embedded Software Engineer for our products. You will develop the control, telemetry, monitoring, and stabilization firmware that maintains the health and lock of our optical transceivers, alongside the tooling required for system bring-up. Collaborating directly with systems, digital, analog, and photonics engineers, you will develop well-defined firmware components through their full lifecycle—from initial requirements to final release—while acquiring deep domain expertise in an emerging field. Core Responsibilities • Develop the lifecycle (requirements, bring-up, testing, and release) of well-defined optical transceiver firmware modules covering control, telemetry, diagnostics, and monitoring. • Implement and refine photonic control and stabilization loops on embedded targets in partnership with analog and photonics design teams. • Partner with hardware engineers during new board bring-up, utilizing oscilloscopes, logic-analyzers, JTAG, and GDB for debugging. • Participate in control and diagnostics design reviews, documenting findings for cross-functional engineering teams. • Operate independently with guidance at key project milestones. Qualifications • Experience delivering firmware to production hardware or customers, with clear ownership of specific components. • Proficiency in C or C++ on resource-constrained targets, combined with Python skills for prototyping, test creation, and data analysis. • Solid understanding of embedded communication buses and peripherals (SPI, I2C, GPIO, UART) and hardware–software co-integration. • Hands-on lab debugging skills using JTAG/GDB, logic-analyzers, and oscilloscopes. • Familiarity with Git and build toolchains such as CMake. • BS or MS degree in Electrical Engineering, Computer Engineering, Computer Science, or equivalent, and 2+ years of professional experience in embedded software engineering. Preferred Qualifications • Experience developing bare-metal firmware and working with RTOS environments (e.g., Zephyr, FreeRTOS). • Experience with hardware-in-the-loop (HIL) test setups, test automation, or firmware CI pipelines. • Knowledge of Embedded Linux and device driver development. • Experience working with optical transceivers, photonic platforms, or high-precision analog/mixed-signal hardware. • Domain understanding in laser physics or wavelength and thermal control systems. We offer competitive compensation. The base salary range for this role determined based on location, experience, educational background, and market data. Salary Range: total compensation goes beyond base salary, it also includes a new hire equity grant, annual performance-based equity, and other rewards that recognize your impact and contribution. $125,000—$145,000 USD Benefits • Comprehensive Health Care Plan (Medical, Dental & Vision) • Retirement Savings Matching Program • Life Insurance (Basic, Voluntary & AD&D) • Generous Time Off (Vacation, Sick & Public Holidays) • Paid Family Leave • Short Term & Long Term Disability • Training & Development • Commuter Benefits • Flexible, hybrid workplace model • Equity grants (applicable to full-time employees) Benefits eligibility may vary depending on your employment status and location. Lightmatter recruits, employs, trains, compensates, and promotes regardless of race, religion, color, national origin, sex, disability, age, veteran status, and other protected status as required by applicable law. Export Control Candidates should have capacity to comply with the federally mandated requirements of U.S. export control laws.