---
title: 'Signal Integrity Engineer at Lightmatter'
canonical: 'https://feeny.ai/job/signal-integrity-engineer-lightmatter-mountain-view-ayx6663v9ev9'
type: 'job'
last_seen: '2026-09-11'
---

# Signal Integrity Engineer at Lightmatter

- **Company:** Lightmatter
- **Location:** Mountain View, CA
- **Compensation:** $157k–$176k
- **Posted:** 2026-08-19
- **Last confirmed live:** 2026-09-11
- **Apply:** https://boards.greenhouse.io/lightmatter/jobs/5382139008?gh_jid=5382139008

## Job description

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 This Role

We are looking for a Signal Integrity engineer to drive the next generation products from concept to development. You will be part of the Signal Integrity, Power Integrity and Packaging team, tasked with influencing the package and system architecture, design, and analysis through lab bring-up to meet the product's signal integrity requirements. This position offers a unique opportunity to solve complex interactions across digital, analog and photonics domains while meeting stringent signal integrity goals.

## Responsibilities

- Plan and execute moderate to complex signal integrity engineering tasks for high-speed interfaces such as PCIe, UCIe and SerDes.
- Analyze high-speed channel characteristics including S-parameters, insertion loss, return loss, and crosstalk to evaluate and optimize signal quality.
- Perform signal integrity analysis and simulations (eye diagram analysis, jitter analysis, equalization) by adapting existing practices and procedures to evaluate design choices.
- Collaborate with cross-functional teams including hardware designers and PCB layout engineers working on individual and team projects that impact the broader engineering function.
- Assist hardware designers in ensuring proper impedance matching, termination, and routing techniques, advising peers on complex signal integrity matters.
- Perform detailed signal integrity measurements and characterization using lab equipment (oscilloscopes, network analyzers, TDRs, VNA) to validate design performance and troubleshoot ill-defined issues.
- Participate in signal integrity design reviews, presenting findings and suggesting creative variations in approach to ensure adherence to design specifications.
- Document and communicate signal integrity analysis results and design guidelines to stakeholders, adapting communication style depending on the audience.

## Qualifications

- B.S. or M.S. degree in Electrical Engineering or relevant field with a minimum of 5 years of related experience.
- Robust professional and specialized knowledge in signal integrity analysis for high-speed interfaces.
- Proficiency in using simulation and analysis tools for signal integrity, including Ansys Siwave, HFSS & Keysight ADS.
- Strong understanding of transmission line theory, impedance matching, and equalization techniques.
- Knowledge of signaling protocols for high-speed interfaces, including SerDes, UCIE, etc.
- Ensure robust signal integrity and timing performance for lower-speed critical interfaces and control buses, such as system clocks, SPI, and I2C.
- Experience with PCB design and layout considerations for high-speed interfaces (layer stack-up, routing, and via design).
- Proficiency in using lab equipment for signal measurement and characterization.
- Ability to write scripts to automate the simulation flow (Python, JavaScript, Ocean scripts, or SKILL).

## Preferred Qualifications

- Strong problem-solving and debugging skills for signal integrity-related issues.
- Understanding of CMOS process technologies and their impact on signal integrity.
- Demonstrated ability to network with new stakeholders and collaborate effectively across teams.
- Ability to work independently, utilizing best judgment to select appropriate courses of action, with work reviewed at critical checkpoints.

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. $157,000—$176,000 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.

## About Lightmatter

## Company Overview
- **One-liner**: Lightmatter builds photonic interconnects and computing infrastructure to eliminate bandwidth bottlenecks in AI and high-performance computing, enabling the next era of AI scaling.
- **Entity Type**: Private (Series D, $850M total funding)
- **Headquarters**: Mountain View, California, USA
- **Founded**: 2017
- **Founders**: Nicholas Harris, PhD (CEO), Darius Bunandar, PhD (Head of Machine Learning), and a third co-founder (Chief Scientist)

## Core Business
- **Primary industry**: Silicon Photonics / AI Infrastructure / Semiconductor
- **Target customers**: Hyperscale data center operators, AI labs (training frontier models), cloud service providers, and enterprise AI teams
- **Mission or purpose**: To make computers keep getting better by using light instead of electricity for data movement, solving the fundamental bandwidth bottleneck that limits AI scaling.

## Products & Services
- **Passage™ Platform**: A family of 3D-stacked silicon photonics interconnects (NPO, OBO, 2D/3D CPO, 3D interposers) that provide "Edgeless I/O"—unlimited bandwidth scaling for AI supercomputers. Key variants include:
  - **Passage M1000 EVK**: Rack-level 3D photonic interposer delivering 114 Tbps across a 4,000 mm² footprint.
  - **Passage L200**: Designed for frontier-scale training, supporting 32–64 Tbps aggregate bandwidth via co-packaged optics (112G PAM4).
  - **Passage L20**: Accelerates optics integration with 12.8 Tbps aggregate bandwidth and 4x pluggable density.
  - **Passage EVK100**: High-bandwidth bidirectional link at 3.2 Tbps per fiber, 1.9 pJ/bit.
  - **Passage EVK50**: 16-wavelength bidirectional link at 800 Gbps per fiber, 2.6 pJ/bit.
- **Guide® Light Engines**: Very Large Scale Photonics technology—a universal light source (hundreds of lasers and photonics components on a single chip) designed to power co-packaged optics across the entire photonics industry.

## Market Standing
- **Valuation**: $4.4 billion (as of October 2024)
- **Key Metric**: $850M total funding raised
- **Notable Investors/Partners**: TSMC, GlobalFoundries, Tower Semiconductor (manufacturing partners); Amkor, ASE (packaging partners); NVIDIA (joined NVLink Fusion ecosystem); standards bodies including Ultra Ethernet, UALink, JEDEC, OIF, IEEE, OCP, and the Advanced Photonics Coalition.
- **Growth Signals**: First-mover in category-defining photonic interconnects; multiple generations of production-ready technology (not vaporware); reference platforms in customer hands; 100,000+ GPU cluster capability; world-first 16-wavelength bidirectional optical DWDM link on standard single-mode fiber (8x leap in bandwidth density); partnerships with top foundries ensure high-volume manufacturing.

## Competitive Advantages
- **Edgeless I/O architecture**: Eliminates the physical chip-perimeter constraint that limits electrical interconnects, enabling bandwidth to scale without bound.
- **Fundamentally better physics**: Photons travel without resistive loss, cross paths without interference, and carry multiple signals on a single fiber—far more efficient than electrons.
- **Deep vertical integration**: From photonic chip design to light engines (Guide) to complete interconnect platforms (Passage), with proprietary 3D stacking technology.
- **Decade-scale roadmap**: Continued bandwidth scaling (114 Tbps today, 1+ Pbps tomorrow) with production-ready silicon validated at scale.
- **Ecosystem lock-in**: Standards body leadership and partnerships with NVIDIA, TSMC, and hyperscalers create high switching costs.

## Strategic Focus
- **Scale AI infrastructure**: Enable 100,000+ GPU clusters for trillion-parameter models, solving the interconnect bottleneck that currently strands hundreds of millions in compute capacity.
- **Productize photonics**: Move from reference platforms to volume production across Passage and Guide families, targeting both training and inference workloads.
- **Expand ecosystem**: Deepen partnerships with hyperscalers, AI labs, and chipmakers (e.g., NVIDIA NVLink Fusion) to make photonic interconnects the default for next-gen data centers.
- **Hire across all functions**: Actively growing engineering, research, sales, and operations teams to scale the company.

## Why Work Here
- **Mission-driven impact**: Work at the intersection of photonics, AI, and semiconductor engineering to solve the most critical bottleneck in AI—data movement. Your work directly enables frontier models and trillion-parameter training.
- **World-class team**: Colleagues from MIT, Caltech, Stanford, and UC Berkeley; published in Nature, Science, ISSCC, ISCA; 100+ patents; team members contributed to black hole simulation software for the Academy Award-winning movie *Interstellar*.
- **Cutting-edge technology**: Not research, not vaporware—multiple generations of production-ready photonic chips in customer hands, with a decade-scale roadmap.
- **Locations**: Mountain View, CA (HQ); Boston, MA; Hsinchu, Taiwan; Toronto, Canada.
- **Benefits**: 401(k), generous vacation policy and holidays, commuter benefits, happy hours, and a strong learning culture (peer-to-peer knowledge sharing across electronics, photonics, machine learning, and more).
- **Culture**: "We are one Lightmatter"—collaborative, cross-disciplinary, and focused on solving hard problems at scale.

## Sources
1. [lightmatter.co/about](https://lightmatter.co/about/)
2. [lightmatter.co](https://lightmatter.co/)
3. [lightmatter.co/people/careers](https://lightmatter.co/people/careers/)
4. [lightmatter.co/people](https://lightmatter.co/people/)
5. [linkedin.com/company/lightmatter](https://www.linkedin.com/company/lightmatter)

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