Software Engineer - Network (C++)

📍 Palo Alto, United States
📍 Seattle, United States

USD 180,000-440,000 per year

MIDDLE

✅ On-site

Tech Stack
Tag name is followed by "@" symbol and proficiency level value. About proficiency levels:

1-2 — basic awareness. Minimal hands-on experience, and a rudimentary understanding of the technology's purpose;

3-6 — daily use. Comfortable and regular usage, capable of handling common tasks and challenges related to the technology;

7-9 — you are an expert, you can teach others, you know all the pitfalls and tricks;

10 — exceptional knowledge, comprehensive understanding, and adeptness in all aspects of the technology, including advanced problem-solving. Think twice before claiming or demanding such level.

AI Algorithms Communication @ 3 Data Analysis Debugging @ 3 Distributed Systems @ 6 GPU HPC Mathematics @ 3 Networking @ 6 Security @ 3 Software Development @ 3

Details

SpaceXAI is building Colossus, a large-scale AI infrastructure platform consisting of massive GPU clusters, high-speed interconnect fabric, and software supporting Grok and frontier AI models. The Colossus Networking team develops and operates a custom, high-performance datacenter network designed for ultra-low latency and high bandwidth across hundreds of thousands of GPUs.

As a Software Engineer on the Colossus Networking team, you will develop core networking software that improves the performance and reliability of the datacenter fabric. Engineers own the full software lifecycle, including design, implementation, deployment, monitoring, and iteration based on real-world performance at scale.

Responsibilities

Develop routing and traffic-engineering algorithms for the Colossus high-performance datacenter network.
Develop highly reliable, real-time software for the switches forming the low-latency, high-bandwidth AI training fabric.
Participate in and lead architecture, design, and code reviews.
Develop prototypes and run experiments to validate design decisions at small and full-cluster scale.
Build tools for software development, deployment, data analysis, visualization, and testing across virtualized environments, hardware-in-the-loop setups, and live production clusters.
Deploy reliable software updates through continuous integration and release systems with rigorous testing and monitoring.

Requirements

Bachelor's degree in computer science, engineering, mathematics, or a related technical discipline, or 2+ years of professional software development experience in lieu of a degree.
Strong development experience in C or C++.
Strong professional experience writing high-performance C/C++ in production environments.
Experience developing, debugging, and deploying software that runs at scale in real-world systems.
Deep knowledge of networking protocols such as UDP, TCP/IP, and RDMA; distributed systems; and large-scale datacenter fabrics.
Background in real-time systems, high-performance computing, low-latency networking, or resource-constrained environments.
Creative problem-solving ability, exceptional analytical skills, and strong engineering fundamentals.
Excellent written and verbal communication skills.
Ability to thrive in a fast-paced, dynamic environment with evolving requirements.
Experience with security considerations in large-scale distributed systems.
Must be willing to work extended hours and weekends as needed.

Benefits

The compensation package includes equity, comprehensive medical, vision, and dental coverage, access to a 401(k) retirement plan, short- and long-term disability insurance, life insurance, discounts, and other perks. SpaceXAI is an equal opportunity employer.