Software Engineer - Networking Software and Services

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. ABOUT THE ROLE: As a backend engineer, you’ll design and build scalable, high-performance systems that power subscriptions infrastructure, new monetized products, user growth, and creator monetization. You’ll work on mission-critical infrastructure that processes millions of transactions, optimizes user acquisition and retention, and enables creators to earn a living through their content. This is a unique opportunity to make a large-scale revenue impact while creating products that users and businesses love. RESPONSIBILITIES: Design and build large scale search infrastructure (real-time indexing, serving, and data pipelines) that handles massive write and query loads with strict latency and reliability requirements Go deep into search internals (indexing, query execution, and relevance) and help shape the technical direction of the core search infrastructure Operate production services end to end, including monitoring, debugging, incident response, and performance optimization Lead and drive incident responses and recovery with your peers. Review and contribute to incident postmortems and hold a high bar for the same BASIC QUALIFICATIONS: 5+ years developing large-scale infrast

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. RESPONSIBILITIES: Design, build, and implement a large-scale distributed system that powers one of the world's largest supercomputing clusters. Dive into the low-level stack to profile, debug, and optimize performance across diverse systems, including GPUs, Linux kernel, networking, and filesystems, to achieve peak efficiency. Collaborate on hardware, software, and algorithm co-design to push the boundaries of AI training. Maintain and innovate on our codebase to ensure scalability and reliability. Develop tools to enhance team productivity and streamline workflows. BASIC QUALIFICATIONS: Systems programming experience in C, C++, or Rust Computer systems fundamentals with a grasp of how computers execute code from transistors to high-level applications. Hands-on expertise with Kubernetes (K8s), including cluster architecture, pod lifecycle, networking (CNI), storage (CSI), service mesh, and production-grade operations PREFERRED SKILLS AND EXPERIENCE: Collaborate in a fast-paced, open environment to design and foundational systems. Strong debugging skills across the full stack — from kernel and OS up through container orchestration layers Deep knowledge of operating systems intern

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. ABOUT THE ROLE: At SpaceXSI, 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-tim

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. ABOUT THE ROLE: We are building one of the world’s largest AI supercomputers from the ground up. As part of the Compute Infrastructure team, you will own both the raw GPU supercomputer and the platform layer that runs on top of it. You will work across the full stack — from low-level GPU kernel optimizations and Linux kernel internals to massive-scale orchestration and virtualization — to make training and inference at SpaceXSI as fast, reliable, and scalable as possible. This is a broad, high-impact role that combines hardcore supercompute and compute infrastructure work. Your contributions will directly accelerate Grok’s training speed and overall AI progress. RESPONSIBILITIES : Design, build, and optimize massive GPU clusters for extreme-scale training and inference workloads Develop and tune low-level CUDA kernels (GeMM, Attention, etc.), using CUTLASS, Tensor Cores, and Nsight for maximum performance Profile, debug, and eliminate bottlenecks across GPU memory hierarchy, networking fabric, filesystems, and multi-GPU operation Collaborate closely with AI research teams to deliver production-grade performance and scalability PREFERRED SKILLS AND EXPERIENCE: Deep low-level syst

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. 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. Developing and constantly improving our tools for observability and configuration management. Collaborate with our hardware teams and external p

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. ABOUT THE ROLE: As an engineer for Consumer Subscriptions (X Premium & SuperGrok), you will own the entire billing and monetization infrastructure powering one of SpaceXSI's fastest-growing revenue organizations. You will build and lead the dedicated engineering team responsible for subscriptions, promotions, global payments, and personalized user experiences at massive scale. This high-impact engineering role offers the opportunity to directly drive significant revenue growth while architecting systems that serve hundreds of millions of users worldwide and shape the future of premium AI and social products. RESPONSIBILITIES: Own the complete billing infrastructure for consumer subscriptions end-to-end, ensuring world-class reliability, security, and scalability. Design and build sophisticated promotional offer infrastructure and internal tools to supercharge the revenue organization. Develop comprehensive communications systems enabling intelligent push, email, and in-app messaging that drive engagement and conversions. Implement market-specific billing methods and compliance solutions to accelerate global expansion. Architect compelling product bundles across the X ecosyst