Full-Time
Principal Firmware Engineer
Lumentum
1,001-5,000 employees
Supplies photonic components for networks
Compensation Overview
$134.8k - $192.5k/yr
San Jose, CA, USA
In Person
Bachelor's, Master's
 Software Engineering (1) |
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- A BS in Electrical Engineering, Computer Engineering, Computer Science, or a related field, or equivalent experience.
- At least 10 years of professional embedded firmware development experience, including ownership of shipped products.
- Expert proficiency in C/C++ for embedded systems, Git source code control, Segger IDE, Python, data analysis tools such as JMP and R, Windows, and Linux.
- Deep experience with real-time operating system development, such as FreeRTOS, and bare-metal firmware, including interrupts, bootloaders, and hardware abstraction layer or low-level drivers.
- Strong skills in board bring-up, debugging, and laboratory tools including JTAG/SWD, logic analyzers, oscilloscopes, optical power meters, and optical wavemeters.
- A solid understanding of hardware/firmware integration and digital interfaces including I2C, SPI, UART, GPIO, ADC/DAC, timers, and DMA.
- The ability to lead technical decisions, drive architecture, and deliver across multidisciplinary teams.
- Hands-on experience with optical component and module calibration and control, including proportional-integral-derivative control, optical power control and automatic power control loops, bias/current tuning, heater and thermal control, thermoelectric cooler control, optical signal monitoring, fault management, and trend-based telemetry.
- Own firmware architecture and the technical roadmap for one or more embedded platforms supporting optical, laser, telecom, or related high-reliability systems.
- Lead end-to-end firmware development from requirements through design, implementation, verification and validation, production release, and sustaining.
- Develop firmware for microcontroller- or microprocessor-based embedded systems using bare-metal firmware, real-time operating systems, and/or embedded Linux, including board bring-up and low-level drivers.
- Define interfaces and protocols across firmware, hardware, field-programmable gate arrays, optics, and host software, including I2C, SPI, UART, CAN, Ethernet, and applicable higher-layer protocols.
- Drive system reliability and quality through fault handling, diagnostics, telemetry, logging, upgrade mechanisms, and robust state-machine design.
- Lead design reviews, code reviews, and root-cause analysis for field issues, and implement corrective and preventive actions.
- Collaborate with Systems, Hardware, Optical Engineering, Test, Reliability, Manufacturing, and Program Management to meet schedule and product goals.
- Direct experience developing firmware or software for optical transceiver modules and subsystems, including bring-up, feature development, and production support.
- Strong familiarity with module management and host interfaces, including CMIS, and experience implementing, debugging, and validating management behaviors such as state machines, paging or banked memory, diagnostics, alarms, and telemetry.
- Experience with optical component control, including lasers and MZ/IQ modulators, proportional-integral-derivative control, performance monitoring, and fault management.
- Understanding of manufacturing test flows and firmware support or application programming interfaces for calibration, characterization, and end-of-line verification, with experience building Python tooling or scripts to support these flows.
Lumentum makes photonic components such as diode lasers and optical modules for data networks, data centers, sensing, and manufacturing. These devices turn electrical signals into light to enable high-speed data transmission and 3D sensing, or to power optical communications in networks and devices. It differentiates itself with a broad, high-volume photonics platform that includes silicon photonics and laser diodes for 3D sensing, designed for scalable, reliable supply to tech ecosystems. Its goal is to improve the speed, flexibility, and efficiency of communication networks and sensing systems to handle growing data traffic.
Company Size
1,001-5,000
Company Stage
IPO
Headquarters
San Jose, California
Founded
2015
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Simplify's Take
What believers are saying
- Q4 fiscal 2026 revenue hit $1.01 billion, up 109% year over year.
- Pump laser shipments rose over 80%, and management expects a fourfold increase.
- First-quarter fiscal 2027 operating margin guidance of 39.5%-40.5% signals strong leverage.
What critics are saying
- Coherent, InnoLight, and Applied Optoelectronics are all racing into 1.6T hyperscaler sockets.
- Lumentum's $7.8 billion debt-extinguishment charge exposed fragile GAAP earnings quality.
- If hyperscalers delay 1.6T orders in 2027, the $1.25 billion quarter disappoints.
What makes Lumentum unique
- Lumentum controls upstream laser engines, not just transceiver assembly, preserving pricing power.
- August 11, 2026 guidance reached $1.225 billion-$1.275 billion before schedule, proving execution.
- The company shipped record 800G modules and started 1.6T production in 2026.
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Benefits
Wellness Program
Flexible Work Hours
Mentorship Program
Professional Development Budget
Growth & Insights and Company News
6 month growth
↑ 3%1 year growth
↑ 3%2 year growth
↑ 3%Lumentum and Coherent, optical component makers for AI data centers, saw shares drop sharply on Tuesday. Lumentum fell 9.9% to $873.31, while Coherent declined 12.8% to $306.43 amid broader selling in richly valued AI-related stocks. The declines weren't company-specific. Both firms recently reported strong results. Lumentum doubled its revenue to $1.01 billion in its fiscal fourth quarter ended 27 June, up 109% year over year. The company expects $1.225 billion to $1.275 billion in revenue this quarter. Adjusted gross margin reached 50.4%, with adjusted earnings per share of $3.23. Management guided to $4.05 to $4.35 this quarter. Coherent posted a record quarter with guidance for continued growth. Both companies cited strong demand for optical components used in AI data centers.
Applied Optoelectronics and Lumentum are competing for dominance in the optical networking market, both capitalising on surging demand from AI data centres. Applied Optoelectronics reported strong second-quarter 2026 results, with data centre revenues reaching $107.66 million, up 140.4% year over year. The company is benefiting from high-speed transceiver demand, particularly 400G and 800G products. Its CATV segment achieved record revenues of $80.6 million, up 43.8% annually. Lumentum posted a 109% year-over-year revenue surge to $1.01 billion in its fourth quarter of fiscal 2026, marking eight consecutive quarters of growth. The company reported record 800G cloud transceiver shipments and launched 1.6T modules, whilst pump laser shipments increased over 80% annually. Both companies are well-positioned in the expanding AI infrastructure market, though Lumentum shows stronger overall revenue growth.
Lumentum CEO Michael Hurlston sold 5,438 shares worth approximately $5 million on 15 August 2026, according to an SEC Form 4 filing. The transaction was non-discretionary, triggered by the vesting of restricted stock units, with shares withheld to cover mandatory tax obligations. The sale represents a 4% reduction in Hurlston's direct holdings, leaving him with roughly 119,000 shares valued at approximately $115.28 million. San Jose-based Lumentum manufactures optical and photonic components for telecommunications infrastructure and data centres. The company has a market capitalisation of $75.4 billion and reported $3 billion in trailing 12-month revenue, though it posted a net loss of $6.9 billion over the same period.
Lumentum Holdings, a San Jose-based manufacturer of optical and photonic products, has seen its stock surge 720.4% over the past year, significantly outpacing the S&P 500's 20.4% gain. In 2026, shares are up 157.9% compared to the index's 13.7% rise. The company's strong performance stems from growing demand for optical components used in AI data centres. Lumentum reported eighth consecutive quarters of revenue growth, with Q4 revenue reaching $1 billion, exceeding Wall Street's $988.6 million forecast. Adjusted EPS of $3.23 also beat expectations of $2.99. The company expects Q1 2027 revenue between $1.2 billion and $1.3 billion, with adjusted EPS of $4.05 to $4.35. The results have prompted widespread analyst price target upgrades, positioning Lumentum as a key hardware enabler in AI infrastructure development.
Lumentum Holdings is emerging as a major beneficiary of AI infrastructure growth, driven by surging demand for optical networking components that rapidly transmit data in AI data centres. Investment firm Rosenblatt Securities projects optical component production capacity could increase 12-fold between 2025 and 2030, yet supply will still trail demand by 50% in 2030. The photonics components supplier reported fiscal Q4 2026 results on 11 August, with revenue jumping 109% year-over-year to just over $1 billion, surpassing analyst estimates of $988 million. Non-GAAP operating margin expanded 21.6 percentage points to 36.6%, whilst adjusted earnings per share rose nearly 3.7 times to $3.23, beating the $2.97 consensus estimate. Shares rose more than 13% following the results announcement.