xAI

Optical Engineer - Memphis

Reposted 6 Days Ago

Be an Early Applicant

2 Locations

In-Office

Junior

Information Technology

The Role

Designs and owns optical and fiber infrastructure for large-scale AI compute clusters, including cabling, link budgets, connectors, transceivers, testing, vendor qualification, manufacturing integration, and commissioning. The role involves debugging optical failures, validating high-speed interconnects, improving rack-scale fiber density, and collaborating with mechanical, networking, facilities, and factory teams. Travel to manufacturing and datacenter sites, extended hours, and hands-on work in active factory and datacenter environments are required.

Summary Generated by Built In

SpaceX was founded under the belief that a future where humanity is out exploring the stars is fundamentally more exciting than one where we are not. Today, SpaceX is actively developing the technologies to make this possible, with the ultimate goal of making life multiplanetary and expanding consciousness to the stars.
SpaceXSI is building Super Intelligence to help humanity understand the universe. Our teams are building the full Super Intelligence stack: from our Colossus supercomputers, to Grok models, to our suite of applications, including Grok Bot, Grok Build, Grok Imagine, Grok Voice, and X. We're creating a powerful flywheel where more compute trains better models, better models power more useful products, and what we learn from people using those products shapes what we build next.

OPTICAL ENGINEER

The Data Center Engineering team designs training and inference compute clusters from first principles, pushing thermal, electrical, and optical systems to the limit of physics. We operate as a highly cross-disciplinary team of mechanical, electrical, optical, and software engineers, all working to maximize the efficiency, reliability, and deployment speed of terrestrial computing to serve rapidly scaling demand.

This team owns compute architecture, datacenter network design, rack builds, connectivity, in-house design of our own computers, and the manufacturing line that builds that compute. As an Optical Engineer, you will own the physical optical layer of that computer: fiber layout, link design, connector and polarity architecture, optics selection, and production of a plant that can be built, tested, and repaired at AI cluster scale.

RESPONSIBILITIES:

Own end-to-end optical and fiber design for AI training and inference fabrics: fiber cabling, cassette/panel architecture, polarity, breakout, reach, and connector strategy (MPO-12/16, SN, MDC, LC, OSFP / QSFP-DD)
Write and verify link budgets for scale-out and scale-up interconnect (SMF/MMF, AOC/DAC, DR/FR/LR, InfiniBand and Ethernet), including loss, reflections, FEC, and realistic install margins
Develop and implement factory tests for optical interconnects including insertion loss, return loss, and polarization
Select and qualify optics, fiber, and connectivity (transceivers, patch, trunks, cassettes, harnesses); own vendor bring-up, failure analysis, and fleet reliability of the optical layer
Deploy and verify end-to-end optical interconnect into the manufacturing line
Lead commissioning and debug: inspect/clean, power meter, OTDR, BER/FEC stats, and volume failure modes (dirty connectors, wrong polarity, wrong map, damaged end-face)
Evolve connectivity toward the next speed and density (800G / 1.6T, CPO/NPO awareness, tighter reaches, higher fiber count per rack)
Work with mechanical and network teams to design structured cabling and raceways with the rack and facilities teams: tray fill, bend radius, pre-term vs field-term, labeling, and a plant that can be built and repaired at hall scale

BASIC QUALIFICATIONS:

Bachelor’s degree in electrical engineering, optical engineering, physics, or an engineering discipline
2+ years of professional experience in fiber layout, optical link design, and/or datacenter/HPC optical engineering

PREFERRED SKILLS AND EXPERIENCE:

Demonstrated ownership of fiber or optical design that was installed and turned up in a datacenter, HPC, or AI-compute environment
Working command of single-mode vs multimode, MPO polarity, insertion/return loss, and 100G+ transceiver classes
Hands-on optical test: inspect/clean, power meter, OTDR or equivalent
Fiber interconnect ownership for AI / high-compute clusters (GPU scale-out fabric, InfiniBand NDR/XDR, RoCE Ethernet 400/800G)
High-density pre-terminated trunk/cassette design and rack-to-spine optical mapping at hall scale
Optics vendor qualification at volume (OSFP, 800G DR8/2xFR4, AOCs, and the failure modes that show up in a real fleet)
Experience designing optical harnesses or cassettes for a manufacturing line, including test coverage and yield
DWDM / campus DCI for cluster-to-cluster or building-to-building connectivity
Familiarity with CPO/NPO, linear-drive optics, and next-gen packaging as it hits the rack
Time at a high-velocity AI cloud, GPU cloud, or custom-compute hardware team

ADDITIONAL REQUIREMENTS:

Must be willing to work extended hours and weekends as needed to support design releases, line bring-up, and cluster deployments
Must be willing to travel to manufacturing and datacenter sites
Ability to work in active datacenter and factory environments, including fiber inspection, cleaning, and live debug

SpaceXSI is an equal opportunity employer. For details on data processing, view our Recruitment Privacy Notice.

Skills Required

Bachelor's degree in electrical engineering, optical engineering, physics, or a related engineering discipline
2+ years of professional experience in fiber layout, optical link design, and/or datacenter or HPC optical engineering
Experience owning fiber or optical designs installed and commissioned in a datacenter, HPC, or AI-compute environment
Knowledge of single-mode and multimode fiber, MPO polarity, insertion loss, return loss, and 100G+ transceiver classes
Hands-on experience with optical inspection and testing using power meters, OTDR, or equivalent tools
Experience with AI or high-compute cluster fiber interconnects, InfiniBand, or RoCE Ethernet
Experience designing high-density pre-terminated trunks, cassettes, and rack-to-spine optical mappings
Experience qualifying optics vendors at volume, including OSFP, 800G DR8/2xFR4, and AOCs
Experience designing optical harnesses or cassettes for manufacturing lines, including test coverage and yield
DWDM or campus DCI experience
Familiarity with CPO, NPO, linear-drive optics, and next-generation optical packaging
Experience at an AI cloud, GPU cloud, or custom-compute hardware team
Willingness to work extended hours and weekends as needed
Willingness to travel to manufacturing and datacenter sites
Ability to work in active datacenter and factory environments, including fiber inspection, cleaning, and live debugging

xAI Compensation & Benefits Highlights

The following summarizes recurring compensation and benefits themes identified from responses generated by popular LLMs to common candidate questions about xAI and has not been reviewed or approved by xAI.

Healthcare Strength — Healthcare is described as comprehensive, including medical, dental, vision, mental health support, and fertility benefits. Additional protections such as disability and life insurance, plus HSA/FSA options, are also outlined.
Equity Value & Accessibility — Equity is positioned as a core component of total rewards alongside high base salaries for technical roles. Pre‑IPO stock grants are highlighted as enabling participation in potential company growth.
Leave & Time Off Breadth — The package includes flexible or generous PTO, paid holidays, and paid sick days. Company materials also describe flexible vacation policies intended to help manage fast‑paced workloads.