Sr. Software Engineer, Linux Kernel

SpaceXSI; Seattle (WA); On-site; USD 180,000 - 330,000; Full time

Benefits offered by this job

Equity

Medical, Vision, and Dental coverage

401(k) retirement plan

Job summary

SpaceXSI seeks a Sr. Software Engineer, Linux Kernel to design, build and operate the leanest OS layers for our AI supercomputers. You will work on the lowest software stack, interface with hardware, and ensure a robust footprint across our network fabric.

Lead kernel development, device drivers, and performance tuning, collaborating with hardware teams to bring up new platforms. Strong C/C++, Linux kernel, and driver experience required; production-grade mindset a must.

Qualifications

• 5+ years of hands-on systems programming in C or C++.
• Deep knowledge of the Linux kernel and its networking stack.
• Experience writing high-performance device drivers for high-speed interfaces.

Responsibilities

• Build and maintain the lean, high-reliability Linux-based operating system that underpins our supercomputer network fabric.
• Write (or rewrite) high-performance device drivers to extract the maximum physical capability from our network and compute hardware.
• Deploy, operate, and debug our platform in production, including rigorous resolution and root-causing of anomalies to ensure reliability and improve observability and configuration management tools.
• Collaborate with our hardware teams and external partners to design the next generation of supercomputer hardware and bring up the OS and software stack on it.

Skills

C/C++

Linux kernel fundamentals

Networking concepts

Kernel debugging

Job description

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.

SR. SOFTWARE ENGINEER, LINUX KERNEL

At SpaceXSI, we design, build, and operate the largest AI supercomputers in the world, from the ground up. As a member of the Platform Core team, you will be responsible for the lowest layers of the software stack on the devices setting the pace for how fast we can push the frontier of AI. Our team’s software interfaces directly with the core hardware of the supercomputer and its network fabric. Our mission is to expose the full capability of that hardware — limited only by physics — to the rest of the stack, all while retaining the smallest, most robust footprint possible.

RESPONSIBILITIES:

• Build and maintain the lean, high-reliability Linux-based operating system that underpins our supercomputer network fabric
• Write (or rewrite) high-performance device drivers to extract the maximum physical capability from our network and compute hardware
• Manage deployment, operation, and debugging of our platform in production, including: rigorous resolution and root-causing of anomalies to ensure the system is constantly improving in reliability and developing and constantly improving our tools for observability and configuration management
• Collaborate with our hardware teams and external partners to design the next generation of supercomputer hardware – and then bring up our OS and software stack on it

BASIC QUALIFICATIONS:

• 5+ years of hands-on systems programming experience in C or C++

PREFERRED SKILLS AND EXPERIENCE:

• Strong operating systems fundamentals (scheduling, memory management, I/O) — you must be able to articulate in extreme detail how a computer works, from the hardware all the way up to high-level applications
• Understanding of computer networking, both in the host (OS stack) as well as common network devices like switches and routers
• Excellent written and verbal communication skills
• Deep knowledge of the Linux kernel and its networking stack — transferable experience with another production-grade kernel is okay, too!
• Proficiency with debugging tools spanning kernel, network, and userspace (e.g., ftrace, perf, Wireshark/tcpdump, eBPF, gdb, and more)
• Experience bringing up new hardware from scratch — you have flashed bare-metal software on a microcontroller with JTAG, or bootstrapped a Linux kernel and rootfs on new hardware
• Demonstrated track record of developing and optimizing device/peripheral drivers — ideally for high-speed interfaces, or with advanced considerations like DMA and cache coherency
• Understanding of major peripheral hardware interface standards (Ethernet, PCIe, I2C, SPI, etc.) — you can critically review a schematic, and debug these interfaces if needed
• Experience with product security, OS/system hardening, and secure boot schemes

COMPENSATION AND BENEFITS:

$180,000 - $330,000 USD

Base salary is just one part of our total rewards package at SpaceXSI, which also includes equity, comprehensive medical, vision, and dental coverage, access to a 401(k) retirement plan, short & long-term disability insurance, life insurance, and various other discounts and perks.