xAI Optical Engineer at SpaceXAI designs and manages the physical optical layer for AI training and inference compute clusters. Responsibilities include fiber layout, link design, optics selection, and production readiness at AI cluster scale.
Responsibilities
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.
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
Qualification
Hands-on optical test
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/HPC optical engineering
Preferred
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
