Sr. Software Engineer, Linux Kernel

SpaceXSI

Palo Alto, CA · Seattle, WAFull-time$200,000–$375,000Posted Nov 4, 2026

About the role

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:

$200,000 - $375,000 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.

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

Responsibilities

  • Build and maintain a lean, reliable Linux-based operating system for the supercomputer network fabric.
  • Develop high-performance device drivers for network and compute hardware.
  • Deploy, operate, debug, and improve the production platform, including observability and configuration management tools.
  • Collaborate with hardware teams and partners to design next-generation hardware and bring up its software stack.

Qualifications

  • At least 5 years of hands-on systems programming experience in C or C++.
  • Strong operating systems fundamentals, including scheduling, memory management, and I/O.
  • Knowledge of host networking, network devices, and the Linux kernel and networking stack.
  • Proficiency with kernel, network, and userspace debugging tools.
  • Experience bringing up new hardware and developing or optimizing device and peripheral drivers.
  • Knowledge of hardware interfaces such as Ethernet, PCIe, I2C, and SPI, and ability to review schematics and debug interfaces.
  • Experience with product security, system hardening, and secure boot.
  • Excellent written and verbal communication skills.

Benefits

  • Equity
  • Medical, vision, and dental coverage
  • 401(k) retirement plan
  • Short- and long-term disability insurance
  • Life insurance
  • Discounts and other perks

Skills mentioned

CC++LinuxDebuggingPerformance OptimizationTCP/IPEmbedded LinuxFirmware DevelopmentSystems EngineeringCybersecurity

About SpaceXSI

Understand the Universe. We are a team of AI technologists and business leaders on a mission to build AI systems that can help humanity understand the world better. https://x.ai/careers

Technology1,001-5,000 employees