Cursor

<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.<br /><br />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.</p><h3>About the Role</h3><p>As a Software Engineer on the <strong>Model Lifecycle and Signals</strong> team at SpaceXAI, you'll own the bridge between frontier models and every user facingCursor product, used at a scale few teams ever see. You'll decide when we use which model, spot where models go off track and build the guardrails to keep them on it, and shape what the next generation of models should learn.</p><p>This role sits at the intersection of infrastructure, data, and product. You'll bring models from preview to production, dig into real-world data to find out what's actually working, and partner with research, inference, product, and data science teams to turn that evidence into better products and better models.</p><p>Every improvement you make compounds across our products and every model we ship.</p><h3>What you'll work on</h3><ul><li><p>Get new frontier models into users' hands the day they're ready, and retire old ones without anyone noticing.</p></li><li><p>Evaluate internal and external preview models before launch and give meaningful feedback to the teams building them.</p></li><li><p>Build <a target="_blank" rel="noopener noreferrer ugc" href="https://cursor.com/docs/cursor-router">Cursor Router</a>: decide which model handles each request, balancing quality, speed, and cost at massive scale.</p></li><li><p>Build the eyes and ears of the product, and the experimentation platform that puts them to work: signals that show where each model shines, where it goes off track, and what 'better' actually means.</p></li></ul><h3>You may be a fit if</h3><ul><li><p>You're an exceptional engineer with a track record of shipping production systems people rely on. You own problems end to end, and you'd rather automate a painful process than repeat it.</p></li><li><p>You've built and operated evaluation, measurement, or model serving systems, such as AI evals, experimentation, ranking/relevance, or routers. You can turn ambiguous "quality" questions into concrete metrics, pipelines, and decisions.</p></li><li><p>You're fluent with data and can collaborate effectively with data scientists and researchers.</p></li><li><p>You have strong taste and real curiosity about model and agent behavior. You try new models the day they come out and have opinions about where each one shines.</p></li></ul><h3>Applying</h3><p>If there appears to be a fit, we'll reach out to schedule 2-3 short technicals. After, we'll schedule an onsite in our office, where you'll work on a small project, discuss ideas, and meet the team.</p><p></p><p>#LI-DNI</p>

Software Engineer, Model Lifecycle and Signals

<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.<br /><br />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.</p><h2><strong>About the role</strong></h2><p>As a Product Engineer on the Grok Connectors team at SpaceXAI, you'll build the integrations that let Grok, Cursor and Grok Bot do real work inside the tools people use every day: Gmail, Outlook, Google Calendar and Drive, Microsoft Teams, OneDrive and SharePoint, GitHub, Slack, finance accounts, and a fast-growing marketplace of third-party MCP plugins. You'll architect, implement, and deploy features end to end, from OAuth sign-in and token handling, to tool schemas and reliability across hundreds of millions of tool calls, to the cards and approval flows users see on web, desktop, and mobile. You'll work directly with enterprise customers and partners to ship connectors that large organizations can trust.</p><p></p><h2><strong>You may be a fit if</strong></h2><ul><li><p>You have an entrepreneurial spirit and love creating outsized business impact.</p></li><li><p>You want AI agents to be genuinely useful, by connecting them to real data and real actions safely.</p></li><li><p>You have deep, practical knowledge of OAuth 2.0 and OIDC and of large provider APIs like Google Workspace and Microsoft Graph, or you're excited to become the expert.</p></li><li><p>You care about reliability: concurrency, retries, rate limits, and observability. You fix root causes, not symptoms.</p></li><li><p>You let data decide what to work on. You size user impact from logs and metrics, and you measure error rates before and after every fix.</p></li><li><p>You're strong in TypeScript and comfortable shipping across backend services and client UI in a large codebase.</p></li><li><p>You enjoy working with customers, partners, QA, and support, and can answer a security review question as clearly as you can fix a bug.</p></li><li><p>Bonus: experience with the MCP protocol, Rust, Kubernetes and multi-cloud deployments, enterprise security and compliance (ZDR, audit logs, Conditional Access), or building LLM agents for automation.</p></li></ul><p></p><h2><strong>Sample projects include</strong></h2><ul><li><p>Building an automated triage system that pulls user reports from feedback channels, groups them by root cause with user-impact estimates, files issues, and starts a first-pass coding agent on each fix</p></li><li><p>Redesigning OAuth token refresh so concurrent requests never burn a single-use refresh token and mark a working connector as disconnected</p></li><li><p>Cutting hundreds of thousands of daily tool-call errors by generating tool definitions from vendors' published API specs, fixing argument mapping, and adding batch tools</p></li><li><p>Shipping Gmail and Outlook draft, reply, and attachment flows, with approval cards so an agent never sends an email without the user's sign-off</p></li><li><p>Launching new partner connectors, from debugging a partner's OAuth metadata to rollout and adoption metrics</p></li><li><p>Making connectors work for enterprise and single-tenant deployments: custom certificate authorities, Entra Conditional Access, admin controls, and compliance reviews with large financial institutions</p></li></ul><p></p><h2><strong>Applying</strong></h2><p>If there appears to be a fit, we'll reach out to schedule 2-3 short technicals. After, we'll schedule an onsite in our office, where you'll work on a small project, discuss ideas, and meet the team.</p>

Software Engineer, Grok Connectors

<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.<br /><br />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.</p><h2><strong>Research Engineer, Synthetic Data</strong></h2><p></p><h3>About the Role</h3><p>As a Research Engineer on the Synth Data team at SpaceXAI, you’ll invent and scale the synthetic data that teaches our models new capabilities. You own the full loop: spotting a capability the model is missing, designing a data generation strategy, building reliable pipelines and verifiers, and validating that the resulting data actually moves the model.</p><p>You form hypotheses about what data will help, build the systems to produce it at scale, run ablations, and read the resulting traces and training signals to understand why it worked (or didn’t). Your datasets go directly into frontier training runs, and shape the development of Grok models.</p><p></p><h3>What you’ll work on</h3><ul><li><p>Designing end-to-end synthetic data recipes that turn raw sources (traces, documents, codebases, workflows) into large, diverse, verifiable task sets.</p></li><li><p>Building strong verification and anti-hacking mechanisms so rewards are simple to compute and hard to game.</p></li><li><p>Controlling difficulty and diversity so data stays learnable and reflects real usage instead of collapsing into templates.</p></li><li><p>Running targeted ablations and analyses that demonstrate a dataset caused a capability improvement (and ruling out grader or data artifacts).</p></li><li><p>Iterating from traces and training results to close specific gaps, then turning successful one-off recipes into reusable infrastructure.</p></li><li><p>Partnering with research and other RL Data teams to translate model capability goals into concrete synthetic data plans.</p></li></ul><p></p><h3>You may be a fit if</h3><ul><li><p>You have research experience on synthetic or post-training data, in industry or academia. You've designed a data generation method, shipped the data into training, and can show its impact to the model you’re training.</p></li><li><p>You have strong software engineering fundamentals and have built non-trivial data pipelines, agent systems, or evaluation frameworks.</p></li><li><p>You have taste for what makes a good training task: hard enough to teach something real, simple enough to grade reliably, and resistant to reward hacking.</p></li><li><p>You are careful and systematic — understanding both aggregate metrics and close reading of raw outputs.</p></li><li><p>You enjoy turning messy, open-ended problems into repeatable, high-quality data production systems.</p><p></p></li></ul><h3>Applying</h3><p>If there appears to be a fit, we'll reach out to schedule 2-3 short technicals. After, we'll schedule an onsite in our office, where you'll work on a small project, discuss ideas, and meet the team.</p>

Research Engineer, Synthetic Data

<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.<br /><br />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.</p><h2><strong>About the Role</strong></h2><p>As a Software Engineer on the <strong>Model Routing &amp; Inference</strong> team at SpaceXAI, you'll build the inference platform that powers every AI interaction in the product. </p><p>This team owns the full inference path: making Cursor's AI faster, more reliable, and more cost-effective at a scale few teams in the world get to operate at. Every agent session, every tab completion, and every chat message flows through your stack.</p><p></p><h3>Example projects include...</h3><ul><li><p>Building and evolving our inference gateway, a single abstraction over every provider's API semantics, so model onboarding becomes a config change.</p></li><li><p>Designing intelligent cross-provider failover so no single provider outage causes user-visible degradation.</p></li><li><p>Designing routing backpressure and admission control so traffic spikes don't cascade into providers.</p></li></ul><p></p><h2>You may be a fit if</h2><ul><li><p>You have deep experience building high-throughput, low-latency distributed systems, especially in inference serving, traffic routing, or real-time data pipelines.</p></li><li><p>You're comfortable reasoning about cost/performance tradeoffs at scale (GPU utilization, provider economics, capacity planning).</p></li><li><p>You have strong software engineering fundamentals and enjoy shipping production systems that handle millions of requests.</p></li><li><p>You make good calls in the gray area: weighing reliability, cost, latency, and user experience when there isn't a single "right" answer.</p></li></ul><p></p><h2>Applying</h2><p>If there appears to be a fit, we'll reach to schedule 2-3 short technicals. After, we'll schedule an onsite in our office, where you'll work on a small project, discuss ideas, and meet the team.</p><p></p><p>#LI-DNI</p>

Software Engineer, Model Routing & Inference

<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.<br /><br />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.</p><h2>Research Scientist</h2><p>SpaceXAI is building the future of coding. We train <a target="_blank" rel="noopener noreferrer ugc" href="https://cursor.com/blog/composer">frontier coding agents</a> and scale RL on real user data to make them increasingly effective.</p><p></p><h2>About the role</h2><p>We’re looking for Research Scientists who can drive effective RL or mid-training research in a small-team setting. You’ll own ambiguous, hard research problems end-to-end: forming hypotheses, designing experiments, building the training/eval/data needed to test them, and pushing results into the next model. You should expect significantly more scope and autonomy than in other research labs.</p><p></p><h2><strong>What you’ll do</strong></h2><ul><li><p>Improve our understanding of RL, what it takes to handle longer horizon tasks, and train with less compute</p></li><li><p>Train graders to improve performance on coding tasks with non-verifiable reward</p></li><li><p>Improve the quality and difficulty of datapoints we use for training our models</p></li><li><p><a target="_blank" rel="noopener noreferrer ugc" href="https://cursor.com/blog/tab-rl">Realtime RL</a> for coding agents</p><p></p></li></ul><h2>You may be a fit if</h2><ul><li><p>You have a deep background in RL and strong machine learning fundamentals</p></li><li><p>You’re an excellent programmer and software engineer</p></li><li><p>You can handle ambiguous research tasks with little guidance</p></li><li><p>You care a lot about data quality, and can dive into the data when appropriate</p></li><li><p>You are truth seeking, aiming to learn more about the science than proving your ideas are correct.</p></li></ul><p>#LI-DNI</p>

Cursor

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Software Engineer, Model Lifecycle and Signals

Software Engineer, Grok Connectors

Research Engineer, Synthetic Data

Software Engineer, Model Routing & Inference

Research Scientist

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