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.

• 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

Set technical direction for firmware architecture across the transceiver product line

Lead and mentor distributed design and development teams across multiple time zones

Establish the review standards and guardrails governing the team's use of AI coding agents

Represent firmware engineering in cross-functional design reviews and customer engagements

• 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

• 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
• Experie…