---
title: 'Software Engineer - Network (C++) at xAI'
canonical: 'https://feeny.ai/job/software-engineer-network-c-xai-palo-alto-qry5gd21vf65'
type: 'job'
last_seen: '2026-10-12'
---

# Software Engineer - Network (C++) at xAI

- **Company:** xAI
- **Location:** Palo Alto, CA / Seattle, WA
- **Posted:** 2026-07-02
- **Last confirmed live:** 2026-10-12
- **Apply:** https://job-boards.greenhouse.io/xai/jobs/5179367007

## 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 understand the universe and help expand humanity’s knowledge and capabilities. We work across the full Super Intelligence stack: compute (Colossus supercomputers), models (Grok), and applications (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.

## ABOUT THE ROLE:

At SpaceXAI, we design, build, and operate Colossus from the ground up. This includes the massive GPU clusters, high-speed interconnect fabric, and the software that makes it all work at unprecedented scale. Colossus powers Grok and our frontier AI models with a custom, high-performance datacenter network that delivers ultra-low latency and massive bandwidth across hundreds of thousands of GPUs.

As a Software Engineer on the Colossus Networking team, you will develop the core networking software that maximizes the performance and reliability of our datacenter fabric. Your work will directly impact training efficiency, model convergence, and the speed at which we can push the frontier of AI.

Our engineers own the full lifecycle of their software — from design and implementation to deployment, monitoring, and iteration based on real-world performance at scale. You will solve hard problems in distributed systems, high-performance networking, and real-time control of one of the largest AI supercomputers on Earth.

## RESPONSIBILITIES:

- Develop routing and traffic-engineering algorithms for the Colossus high-performance datacenter network.
- Develop highly reliable, real-time software designed to run on the switches that form the backbone of our low-latency, high-bandwidth AI training fabric.
- Participate in and lead architecture, design, and code reviews.
- Develop prototypes and run experiments to validate key design decisions at both 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.

## BASIC QUALIFICATIONS:

- Bachelor’s degree in computer science, engineering, math, 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++.

## PREFERRED SKILLS AND EXPERIENCE:

- 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 (UDP, TCP/IP, RDMA, etc.), 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 with 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.

## COMPENSATION AND BENEFITS

$180,000 - $440,000 USD

Base salary is just one part of our total rewards package at SpaceXAI, 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. SpaceXAI is an equal opportunity employer. For details on data processing, view our [Recruitment Privacy Notice](https://x.ai/legal/recruitment-privacy-notice).

## About xAI

## Company Overview
- **One‑liner**: xAI builds artificial intelligence systems to accelerate human scientific discovery and “understand the universe,” with products spanning frontier reasoning models, real‑time voice, and generative media.
- **Entity Type**: Private (last funding round: Series E, January 2026; acquired by SpaceX in February 2026)
- **Headquarters**: Palo Alto, California, USA (additional offices in Seattle, WA; Memphis, TN; London, UK)
- **Founded**: 2023
- **Founders**: Elon Musk

## Core Business
- Primary industry: Artificial Intelligence (AI research, large language models, voice AI, generative media)
- Target customers: B2B (developers via API), B2C (consumers via Grok on 𝕏, SuperGrok subscriptions), Enterprise & Government (xAI for Government)
- Mission: “To understand the universe” – building AI that extends what humanity can know and do.

## Products & Services
- **Grok (base models)** : A conversational AI assistant modeled after *The Hitchhiker’s Guide to the Galaxy*, available on the 𝕏 platform and via API.
- **Grok 4 / Grok 4 Heavy**: The most intelligent reasoning models, featuring native tool use and real‑time search integration (SuperGrok and Premium+ tiers).
- **Grok Voice Agent API / Voice Agent Builder**: Create custom voice agents in under two minutes (no‑code) – includes speech‑to‑text, text‑to‑speech, custom voice cloning, and multilingual support.
- **Grok Imagine API**: State‑of‑the‑art video generation API (quality, cost, latency).
- **Grok‑1.5 / Grok‑2 / Grok‑2 mini**: Earlier model releases with improved reasoning and 128K context length.
- **PromptIDE**: An integrated development environment for prompt engineering and interpretability research.
- **xAI for Government**: A suite of frontier AI products tailored for U.S. government customers.
- **Colossus Supercomputer**: 200,000‑GPU cluster built in 122 days, used for training xAI models; now also leased to Anthropic (Colossus 1 agreement).

All products are delivered as SaaS, API, and model weights (open‑source release of Grok‑1).

## Market Standing
- **Valuation / Funding**: 
  - Series B (May 2024): $6 B 
  - Series C (Dec 2024): $6 B (led by A16Z, BlackRock, Fidelity, Kingdom Holdings, Lightspeed, MGX, Morgan Stanley, OIA, QIA, Sequoia, Valor, Vy Capital, others)
  - Series E (Jan 2026): $20 B
  - Acquisition by SpaceX announced Feb 2, 2026 (terms not disclosed).
- **Key Metric**: Total disclosed funding ~$32 B; annual revenue not publicly available.
- **Notable Investors/Partners**: A16Z, BlackRock, Fidelity, Sequoia Capital, Morgan Stanley, Kingdom Holdings, Lightspeed, MGX, Valor Equity Partners, Vy Capital, Anthropic (Colossus deal), U.S. Department of War (selected Dec 2025).
- **Growth Signals**: 
  - Rapid scaling from founding to 200K‑GPU cluster in 122 days.
  - Over 214 open roles listed on Greenhouse as of mid‑2026.
  - #1 on Big Bench Audio (Grok 4 audio performance).
  - Expanded into voice agents, video generation, and government verticals within 3 years.
  - Acquisition by SpaceX signals deep integration with space‑tech resources.

## Competitive Advantages
- **Compute infrastructure**: Colossus supercomputer – one of the largest GPU clusters in existence, enabling faster training and larger models.
- **Model performance**: Grok 4 claims “most intelligent model in the world” with top benchmarks (Big Bench Audio #1).
- **Vertical integration**: Tight coupling with 𝕏 platform for data, distribution, and real‑time world knowledge.
- **Speed of execution**: “Move quickly and fix things” culture; built Colossus in 122 days.
- **Government contracts**: Early access to public‑sector AI markets (U.S. Department of War).
- **Talent density**: Small, focused team of researchers and engineers; in‑person work accelerates iteration.

## Strategic Focus
- **Continue advancing frontier reasoning** (Grok 4 Heavy, next‑gen models).
- **Expand voice and multimodal APIs** for developers (Voice Agent Builder, Custom Voices Library).
- **Deepen government / defense partnerships** (xAI for Government, Department of War).
- **Scale infrastructure** post‑acquisition via SpaceX resources.
- **Remain “open” where strategic** (open‑source release of Grok‑1 weights).

## Why Work Here
- **Culture**: “Ambitious goals, fast execution” – rejects consensus in favor of first‑principles reasoning. In‑person work prioritized (Palo Alto, Seattle, Memphis, London).
- **Benefits**: 
  - Competitive cash + equity compensation.
  - Comprehensive medical, dental, vision, disability, life insurance.
  - 401(k) plan, fertility benefits, flexible vacation.
  - Visa sponsorship offered.
- **Engineering culture**: No recruiters for assessments – applications reviewed directly by technical team. Interview process: application → screening → technical interviews → offer.
- **Mission‑driven**: Opportunity to work on frontier AI models that aim to “advance humanity.”
- **Perks**: In‑person collaboration, fast‑paced environment, ownership of meaningful projects.

## Sources
1. [x.ai/company](https://x.ai/company)
2. [x.ai/careers](https://x.ai/careers)
3. [job-boards.greenhouse.io/xai](https://job-boards.greenhouse.io/xai)
4. [x.ai/news](https://x.ai/news)
5. [x.ai/careers/open-roles](https://x.ai/careers/open-roles)

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