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! We are hiring a Principal Digital Architect for high-speed photonic (mixed-signal) communication chips. The selected candidate will partner with external facing teams at Lightmatter and the internal engineering team to deliver groundbreaking products to the market. As an architect, you will provide detailed technical documents that describe what needs to be built to the engineering team. This will require a solid understanding of process technology, state of the art in chip design, and clear communication skills. You will represent the company externally at technical conferences as an example of our technical leadership. In this role, you will be defining the architecture of the digital circuits that enable a ground-breaking photonic-based communication fabric. Your work will not only enable the AMS/photonic devices at low-level but also enable the necessary interfaces with the firmware/software. You will interact directly with our vendors and our customers. You will also define the product and technological roadmaps along with suitable design and verification methodologies. You will report directly to the Sr. Director of Architecture, but you will also work closely with our digital, analog, photonic, and software teams. We are looking for an experienced, hands-on digital architect with broad AMS product experience who can contribute immediately across digital, analog, photonics, and firmware teams. Photonic circuit experience is preferred; big-picture thinking is required over narrow specialization. Join a tight-knit team where each individual’s contributions directly influence the success of the company and product. You'll have the opportunity to build a new kind of computer from the ground up and to solve groundbreaking challenges along the way. Work with people who love to build and who thrive in technically diverse environments where great ideas are prioritized. Responsibilities • Be the digital architecture owner of Lightmatter’s Passage product. • Responsible for the digital architecture from initial concept through high-volume production. Work closely with the technical program manager(s) to plan, organize, and execute. • Lead direct collaboration with top tier semiconductor customer(s) throughout the product development process at the system architecture level. • Architect and specify system level digital designs integrating complex AMS and photonic circuits. These circuits include high-speed drivers and receivers, SerDes, ADC/DAC, photonic modulators and detectors. • Collaborate with the product team to develop our future technological and product roadmap. • Work closely with test and validation engineers to validate hardware against simulation prediction. • Actively collaborate and provide clear architectural direction to RTL, DV, analog, photonics, and firmware teams, bridging disciplines and unblocking execution. • Own digital control architecture for AMS and photonic circuits: stabilization algorithms, bias control, thermal tuning, and adaptive calibration, from specification through RTL definition and silicon validation. • Lead silicon bring-up alongside validation teams, defining link training sequences, correlating hardware against simulation, and iterating on control algorithms from measured data.  Qualifications  • 12+ years and a Masters’ degree in Electrical or Computer Engineering • In-depth knowledge of power-efficient digital design flow for high-speed AMS electronics, preferably on photonic communication channels. • Proven track record of delivering successful high-volume silicon in the market. Also, proven understanding of silicon product development flow. • Demonstrated ability to ramp quickly into new domains and drive toward clarity with incomplete information across cross-functional teams. • Hands-on RTL development experience for AMS control logic, state machines, and interface blocks. Specification authorship alone is insufficient. Device bring-up, closed-loop control, and DSP experience required. • Demonstrated strong problem solving skills specifically pertaining to problems that do not have obvious solutions, able to hold the big picture across digital, analog, photonic, and firmware domains while engaging implementation detail when needed. Deep specialists who cannot bridge adjacent domains are not the target profile. • Demonstrated strong customer communication, with timely responses and consistently positive feedback. Preferred Qualifications • Experience with SoC architecture, including digital interfaces, configuration networks, embedded processor subsystems, and debug infrastructure. • Experience with hardware-software co-design, including register map definition, interrupt and DMA architecture, firmware interface specification (calibration, power/boot sequencing, real-time telemetry), and validation via co-simulation or FPGA emulation. • Ability and desire to collaborate in a cross-disciplinary team. • Power user of multiple development tools, including CAD tools, SPICE simulators, IBIS-AMI simulators, and general programming languages (e.g., MATLAB or Python). • Willing and able to learn quickly. Self-starter with a “no task is too big or small” attitude. • Innovative and flexible; realizes that a one-size-fits-all approach will not always solve the problem at hand. • Data-driven and analytical; translates numbers into actionable strategies. • Process-oriented and programmatic: builds structure through processes that can be relied upon across the organization. • Understanding of SerDes PCS layer and equalization along with forward error-correction schemes. 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. $217,000—$325,000 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.