Colossus Networking Software Engineer - C++ (Low-Latency)

xAI; Palo Alto (CA); On-site; USD 260,000 - 380,000; Full time

Job summary

xAI is seeking a Software Engineer for the Colossus Networking team to design and implement core networking software powering the company's GPU datacenter fabric.

You will own components from design to deployment, including routing algorithms, real‑time control, testing, and performance tuning across extensive clusters.

Ideal candidates bring strong C/C++ experience, knowledge of networking protocols, and a track record delivering scalable, reliable systems in fast‑paced environments.

Qualifications

• BS/BA in CS, engineering, math, or related field or 2+ years of software development experience.
• Strong development experience in C or C++.
• Experience with high-performance, scalable software in production is a plus.
• Deep knowledge of networking protocols (UDP, TCP/IP, RDMA) and distributed systems.

Responsibilities

• Develop routing and traffic-engineering algorithms for the Colossus high-performance datacenter network.
• Develop highly reliable, real-time software designed to run on switches forming the backbone of the low-latency 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 and live production clusters.
• Deploy reliable software updates through CI/CD with testing and monitoring.

Skills

C/C++

Networking concepts

Distributed systems

Real-time systems

Education

Bachelor’s degree in computer science, engineering, math, or related technical discipline

2+ years of professional software development experience

Job description

xAI is seeking a Software Engineer for the Colossus Networking team to design and implement core networking software powering the company's GPU datacenter fabric.

You will own components from design to deployment, including routing algorithms, real‑time control, testing, and performance tuning across extensive clusters.

Ideal candidates bring strong C/C++ experience, knowledge of networking protocols, and a track record delivering scalable, reliable systems in fast‑paced environments.