About this role
The Data Center Engineering team at xAI is responsible for designing the training and inference compute clusters from fundamental principles, focusing on pushing the limits of thermal, electrical, and optical systems. This cross-disciplinary team comprises mechanical, electrical, optical, and software engineers, collaborating to maximize the efficiency, reliability, and deployment speed of terrestrial computing to meet rapidly scaling demand. The team manages aspects of compute architecture, datacenter network design, rack builds, and the in-house design and manufacturing of the compute hardware itself.
This Optical Engineer role is central to this effort, focusing specifically on the physical optical layer of these AI clusters. The individual will be accountable for the entire optical and fiber design process, including link design, connector strategy, and the production of a scalable manufacturing plant for optical components. The role exists to ensure the physical interconnects within the AI infrastructure are robust, efficient, and reliable at scale.
Candidates who thrive on challenging problems, possess strong work ethic, and can communicate technical details clearly will be well-suited for this position. This role requires hands-on contribution across multiple engineering domains and an ability to deliver excellence under pressure.
What you will do
- Own the end-to-end optical and fiber design for AI training and inference fabrics, covering fiber cabling, cassette/panel architecture, polarity, breakout, reach, and connector strategy.
- Develop and verify link budgets for scale-out and scale-up interconnects, including various fiber types and protocols such as InfiniBand and Ethernet.
- Develop and implement factory tests for optical interconnects to assess metrics like insertion loss and return loss.
- Select and qualify necessary optics, fiber, and connectivity components, managing vendor bring-up, failure analysis, and fleet reliability.
- Deploy and verify end-to-end optical interconnects into the manufacturing line.
- Lead commissioning and debugging activities, inspecting components using tools like OTDR and analyzing volume failure modes.
- Evolve connectivity solutions toward higher speeds and densities, such as 800G and 1.6T technologies.
What you need
- A Bachelor’s degree in electrical engineering, optical engineering, physics, or a related engineering discipline is required.
- The candidate must possess at least two years of professional experience in fiber layout, optical link design, and/or datacenter/HPC optical engineering.
- Demonstrated ownership of fiber or optical design that has been installed and operationalized in a datacenter, HPC, or AI-compute environment is essential.
- Proficiency in understanding single-mode versus multimode fiber, MPO polarity, insertion/return loss, and 100G+ transceiver classes is required.
- Hands-on experience with optical testing methods such as inspection, cleaning, power metering, and OTDR is necessary.
- Experience owning fiber interconnects for AI/high-compute clusters, including GPU scale-out fabrics and InfiniBand/RoCE Ethernet.
- Familiarity with designing optical harnesses or cassettes for a manufacturing line, including test coverage and yield.
Nice to have
- 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
- Experience designing optical harnesses or cassettes for a manufacturing line, including test coverage and yield
- Familiarity with CPO/NPO, linear-drive optics, and next-gen packaging as it hits the rack
Benefits
- Work ethic and strong prioritization skills are important.
- Strong communication skills are important.
Skills and tech stack
Questions candidates ask
What is the remote policy for this role?
The posting does not specify a remote work policy for this position.
What is the compensation structure?
The salary information is not provided in the job posting.
What is the primary technology stack involved?
The role involves fiber layout, link design for interconnects like InfiniBand and Ethernet, and managing optics such as OSFP and 800G transceivers.
What is the team structure like?
The team operates as a highly cross-disciplinary group involving mechanical, electrical, optical, and software engineers, with a flat organizational structure.