Senior or Principal Firmware Engineer - Optical Transceivers

Molex is an industry leader in transforming optical network infrastructure with an unwavering commitment to speed, reliability, and performance. We proudly engineer high-performance systems for critical, fast-growing industries including data centers, telecom, medical, and industrial automation. Our team develops an advanced portfolio of optical solutions, ranging from cutting-edge optical connectivity products-such as expanded beam connectors, fiber management, adapters, and hybrid copper/fiber solutions for medical systems-to end-to-end optoelectronic solutions featuring cages, connectors, optical transceivers, and cable assemblies. Supporting extreme data rates from 100 Mbps to 1.6 Tbps across long-haul distances up to 80km+, we deliver complete wavelength management and turnkey OEM solutions. Come join Molex and help build the future of global connectivity.

Molex is seeking a highly skilled Senior or Principal Firmware Engineer to join our Optical Systems Business Unit in Fremont, California. In this role you will drive firmware engineering development for next-generation optical transceivers, including OSFP and QSFP-DD form factors at 800G and 1.6T serving datacenter and telecom markets. The ideal candidate brings deep expertise in firmware design, development and verification for optical communication products. At this Senior level, the Firmware Engineer collaborate with Product Management, Hardware, Operations, and Field Application Engineering teams to drive transceiver products from concept through volume production. This role requires both domestic and international travel.

This position is open at both the Senior and Principal level. Final level and compensation will be determined by the candidate's experience, technical depth and demonstrated scope of technical leadership.

What You Will Do

• Design, develop and verify CMIS-compliant firmware for optical transceivers
• Design, implement and calibrate control loops for electro-optical components
• Port, integrate and test DSP chip driver software on target platforms
• Design and develop firmware and GUI-based tools for evaluation boards (EVBs) to streamline debugging, lab testing and performance validation
• Ensure product performance, reliability and quality through critical code reviews, test design and analysis
• Enhance and maintain the firmware codebase, ensuring comprehensive documentation, robust version control and upgrade management
• Implement and maintain secure boot and signed firmware image workflows to meet customer and hyperscaler security requirements
• Apply AI coding agents across development, test and debug workflows - while owning correctness, timing and hardware behavior that agents cannot verify on their own
• Support New Product Introduction (NPI) and Application Engineering teams in bringing products to market
• Troubleshoot and resolve operational and customer issues by analyzing use cases, reproducing issues in the lab and implementing solutions

Additional Scope at the Principal Level

Set technical direction for firmware architecture across the transceiver product lineLead and mentor distributed design and development teams across multiple time zonesEstablish the review standards and guardrails governing the team's use of AI coding agentsRepresent firmware engineering in cross-functional design reviews and customer engagements

Who You Are (Basic Qualifications)

• Bachelor's degree in computer engineering, electrical engineering, or a related field
• 7+ years of experience in firmware design and development for communication or related products
• Experience programming in C/C++ and Python
• Experience with bare-metal and RTOS-based firmware development and optimization
• Experience with bus protocols such as I2C, I3C, SPI, PCIe and MDIO
• Hands‑on experience with lab equipment such as oscilloscopes, signal generators, OSA and VOA
• Experience with PID control loops involving DAC, ADC, TEC and PIC

What Will Put You Ahead

• 10+ years of firmware development experience, including leading or mentoring engineers on technical projects (expected for consideration at the Principal level)
• Experience developing CMIS-compliant firmware for pluggable optical transceivers
• Experience with high‑speed form factors such as OSFP, QSFP‑DD or QSFP112 at 400G and above
• Experience porting and integrating vendor DSP or PHY driver SDKs on embedded targets
• Experience building GUI‑based lab and test tools using Qt, PyQt or an equivalent framework
• Experience using AI coding assistants in a professional development workflow, including reviewing and validating generated code
• Experience with Git version control and CI/CD pipelines
• Background in optical technologies and electro‑optical component behavior

For this role, we anticipate paying $165,000 - $240,000 per year. This role is eligible for variable pay, issued as a monetary bonus or in another form.

At Koch companies, we are entrepreneurs. This means we openly challenge the status quo, find new ways to create value and get rewarded for our individual contributions. Any compensation range provided for a role is an estimate determined by available market data. The actual amount may be higher or lower than the range provided considering each candidate's knowledge, skills, abilities, and geographic location. If you have questions, please speak to your recruiter about the flexibility and detail of our compensation philosophy.

Hiring Philosophy

All Koch companies value diversity of thought, perspectives, aptitudes, experiences, and backgrounds. We are Military Ready and Second Chance employers. Learn more about our hiring philosophy here.

Who We Are

At Koch, employees are empowered to do what they do best to make life better. Learn how our business philosophy helps employees unleash their potential while creating value for themselves and the company.

Our Benefits

Our goal is for each employee, and their families, to live fulfilling and healthy lives. We provide essential resources and support to build and maintain physical, financial, and emotional strength - focusing on overall wellbeing so you can focus on what matters most. Our benefits plan includes - medical, dental, vision, flexible spending and health savings accounts, life insurance, ADD, disability, retirement, paid vacation/time off, educational assistance, and may also include infertility assistance, paid parental leave and adoption assistance. Specific eligibility criteria is set by the applicable Summary Plan Description, policy or guideline and benefits may vary by geographic region. If you have questions on what benefits apply to you, please speak to your recruiter.

Additionally, everyone has individual work and personal needs. We seek to enable the best work environment that helps you and the business work together to produce superior results.

Equal Opportunities

Equal Opportunity Employer, including disability and protected veteran status. Except where prohibited by state law, some offers of employment are conditioned upon successfully passing a drug test. This employer uses E-Verify. Please click here for additional information. (For Illinois E-Verify information click here, aqui, or tu).