Sr. Software Engineer, Network (C++)

SpaceXSI•Palo Alto, CA

1d•$200,000 - $375,000

About The Position

SpaceXSI is building Super Intelligence and developing the full Super Intelligence stack, including Colossus supercomputers, Grok models, and applications. The Colossus Networking team designs, builds, and operates the high-performance datacenter network that supports frontier AI models. This role develops core networking software to maximize the performance and reliability of that network, directly affecting training efficiency, model convergence, and AI development speed. The engineer owns software throughout its lifecycle, from design and implementation through deployment, monitoring, and iteration based on production performance. The work involves distributed systems, high-performance networking, and real-time control of a large AI supercomputer.

Requirements

Bachelor’s degree in computer science, engineering, math, or another technical discipline, or 5+ years of professional software development experience in lieu of a degree.
Development experience in C or C++.

Nice To Haves

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.

Responsibilities

Develop routing and traffic-engineering algorithms for the Colossus high-performance datacenter network.
Develop highly reliable, real-time software for switches in the AI training fabric.
Participate in and lead architecture, design, and code reviews.
Develop prototypes and conduct 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 production clusters.
Deploy reliable software updates through continuous integration and release systems with rigorous testing and monitoring.