Security Engineer - Technical Staff Member

About Mithril Mithril builds AI infrastructure to make GPU computing accessible for enterprises, AI startups, and research organizations. Customers include LG AI Research, Saronic, and the Broad Institute. Founded by a former Google DeepMind research scientist and a Stanford CS PhD, Mithril has raised $80 million in seed and Series A funding from Sequoia Capital, Lightspeed Venture Partners, and others. Over the past year, platform revenue has grown more than sixfold. Fast Company named Mithril the 8th Most Innovative Company in Artificial Intelligence for 2026. The team is moving from bare-metal operations to a cloud-native, multi-provider platform, introducing an auction and flexibility model. This is a chance to help shape the platform from the earliest stages. Role Overview This Software Engineer - Technical Staff Member position works across three core areas: Consumption: Developer-facing product, billing, and API Platform: Orchestration and marketplace solutions Supply: Cloud provider integrations and capacity management Engineers here take on substantial ownership, building features end-to-end that support critical customer workloads and drive revenue. The work spans backend systems, marketplace logic, and customer interfaces. Expect to see the impact of architectural decisions on Mithril’s growth and scalability. What Makes This Role Unique Unlike many early-stage infrastructure roles, this job combines deep systems work with product-facing challenges. Engineers contribute to the orchestration engine that manages GPU capacity across providers and the interfaces customers use to reserve, bid, and utilize resources. The systems developed here handle financial transactions, real workloads, and market mechanisms such as spot auctions, reservation pricing, and capacity allocation. For those interested in the mechanics of GPU infrastructure markets and building the technology that powers them, this role offers direct involvement. Location This role is based in Palo Alto or the San Francisco Bay Area.

About Us At vinci4d, we are revolutionizing the hardware design landscape with our cutting-edge AI assistant, aimed at empowering engineers to accelerate their design iterations by a staggering 1000 times.Our innovative foundation model, driven by geometry and physics, is tailored for each category of part design.We are on the lookout for passionate individuals who thrive on product development to enhance our Minimum Viable Product (MVP).Your ResponsibilitiesAs a pivotal member of our team, you will design and develop the essential pipelines and tools that transform our vision into reality. Your contributions will significantly expedite our development processes by facilitating smooth transitions from code development to deployment. Key responsibilities include:Enhancing product features for scalability and developing advanced APIs to support intricate engineering workflows.Establishing and integrating LLM or VLM infrastructure.Implementing an MLOps framework for training deep learning models using geometry and physics data.Collaborating with early customers and design partners to strategize and prioritize the development roadmap.Building and deploying critical product features.Gaining invaluable experience while creating products that resonate with engineers, and learning about the entrepreneurial journey.QualificationsA minimum of 6 years in developing and delivering features within the high-performance computing domain.Expertise in C++, Python, or any relevant language necessary for system setup, along with familiarity with tools such as gRPC, Protocol Buffers, Docker, Kubernetes, and Bazel.Experience with cloud computing for data generation, scraping, and assisting data science teams in model training with MLOps is a plus.CUDA experience is desirable but not mandatory.Frontend development experience is a bonus.Prior experience in a startup environment will be highly valued.You’ll Thrive in This Role If YouAre enthusiastic about entrepreneurship and the process of transforming ideas from concept to reality.

About SimileAt Simile, we believe in revolutionizing decision-making by simulating the complexities of society. Just as pilots and surgeons train in controlled environments, we aim to equip organizations with the ability to anticipate human behavior through advanced AI simulations. Our pioneering research has established a new frontier in AI-based modeling, allowing us to forecast human behavior across various scenarios and scales.With substantial backing of $100 million from prominent investors including Index Ventures and AI luminaries such as Andrej Karpathy and Fei-Fei Li, we are committed to pushing the boundaries of artificial intelligence.Join Our Infrastructure TeamThe Infrastructure team at Simile is crucial to our platform's success. We design and implement the foundational systems that enable our AI agents to function securely and efficiently on a large scale. We specialize in high-scale cloud networking and distributed systems, ensuring enterprise-grade privacy.Our Work is Organized Around Three Key Pillars:Cloud Foundation: Overseeing our multi-cloud environment (AWS/GCP) to ensure high availability and cost-efficiency through Infrastructure-as-Code.Enterprise Deployments: Creating streamlined pathways for VPC peering, PrivateLink, and BYOC (Bring Your Own Cloud) architectures tailored for our largest clients.Platform & Reliability: Developing CI/CD pipelines and observability stacks (including p99 latency tracking and SLOs) that empower our entire engineering organization to deliver safely and effectively.Role OverviewWe are on the lookout for a driven Infrastructure Engineer who is passionate about navigating the intricacies of modern deployment strategies. You will take charge of our infrastructure roadmap from conception through to operational execution, ensuring our platform remains resilient, compliant, and primed for global scalability.Key ResponsibilitiesArchitect Multi-Cloud Environments: Design and expand multi-region architectures across AWS and GCP, addressing global data residency and failover needs.Enhance Engineering Velocity: Collaborate with Product Engineering, Research, and Security teams to develop internal tools and paved pathways that accelerate development and empower engineering teams.

About UsAt vinci4d, we are pioneering a revolutionary co-pilot for hardware designers, aiming to empower 9 million mechanical engineers to accelerate their design processes by a factor of 1000.Our innovative approach involves developing a geometry and physics-driven foundation model tailored for diverse part designs.We are proud to have secured initial funding from Khosla Ventures, propelling us forward in our mission.About YouYou are a passionate Computational Fluid Dynamicist skilled in developing flow solvers for intricate geometrical applications. Your expertise encompasses external flows over dynamic vehicles (aircraft, missiles, automobiles), as well as fluid movement through machinery such as ducts, turbo-machinery, refrigeration systems, and computer heat sinks. Terms like conjugate heat transfer, multi-physics applications, and complex geometries excite you.Your ResponsibilitiesDesign, develop, and deploy simulation codes for single and multi-physics configurations, emphasizing Conjugate Heat Transfer.Optimize code performance on contemporary architectures, including GPUs.Implement advanced linear and nonlinear solvers to reduce time to solution.Collaborate in strategizing, planning product roadmaps, and prioritizing development alongside early customers and design partners.Develop and launch critical product features.Engage in continuous learning while creating products that resonate with engineers, gaining insights into entrepreneurship.

About UsIn a world where pilots and surgeons practice in simulated environments, we at Simile are pioneering the future by transforming how society's most critical decisions are modeled and understood.We have created the first AI simulation of society, filled with generative agents that reflect real human behavior. Our groundbreaking research has established the viability of AI-driven simulation and we are currently advancing a Foundation Model designed to predict human actions in diverse scenarios and at any scale.With $100M in funding from prominent investors such as Index Ventures, Hanabi, A*, Bain Capital Ventures, and leading AI figures like Andrej Karpathy and Fei-Fei Li, we are poised to revolutionize our field.Your OpportunityAs a Product Engineer - Member of the Technical Staff, you will be crucial in developing the platform that leverages our foundational model. This role is not limited to UI construction; it involves designing robust infrastructure and interfaces to facilitate complex multi-agent simulations for elite organizations worldwide.We seek full-stack engineers who can seamlessly integrate advanced AI research with production-ready enterprise software. You will architect and scale systems that empower clients to manage thousands of generative agents, observe emergent behaviors, and extract meaningful insights from simulated societies.Key Responsibilities:End-to-End Ownership: Lead the product development lifecycle for new enterprise solutions, from initial design through backend services to user-centric components and APIs.Collaborative Product Development: Work closely with product managers, designers, and customers to simplify complex human behavior simulations into intuitive interfaces.System Evolution: Develop and refine systems that enhance customer workflows, ensuring reliability, performance, and scalability as we model human behavior on a global scale.Technical Excellence: Write clean, well-tested code and engage in thorough code reviews to uphold high standards of system quality and safety in production.Pragmatic Shipping: Balance the need for a sound technical architecture with the urgency to deliver incrementally and learn from real-world applications.

About xAIAt xAI, we are on a mission to develop advanced AI systems that enhance our understanding of the universe and help humanity achieve its knowledge goals. Our dedicated team is small yet highly driven, emphasizing engineering excellence. We value individuals who thrive on curiosity and are eager to tackle challenges head-on. With a flat organizational structure, we empower all employees to take initiative and contribute meaningfully to our mission. Exceptional work ethic, prioritization skills, and strong communication abilities are essential for success in our collaborative environment. About the RoleWe are in search of outstanding engineers eager to embark on an innovative project aimed at integrating Grok into every aspect of our Advertising Platform. We seek individuals with extensive experience in developing high-performance advertising products and systems at scale, encompassing bidding, auction, marketplace dynamics, ranking, prediction, and product functionalities. Your expertise will help us leverage xAI’s technology stack to revolutionize our advertising solutions.Your ResponsibilitiesUtilize state-of-the-art Grok models to enhance all facets of our advertising stack, including candidate selection, ranking, auctions, campaign optimization, creative development, and improving the advertiser experience.Take ownership of systems and products that drive significant revenue for the company.Who You AreYou possess 3+ years of industry experience in creating large-scale, high-throughput, AI-driven advertising solutions.Technical ProficienciesProficient in Python, Jax, and Rust.LocationOur engineering team is based in Palo Alto, CA. While we typically work from the office five days a week, we offer flexible work-from-home options when needed.Interview ProcessUpon submitting your application, our team will review your resume and documentation of your outstanding work. If your application meets our criteria...

About xAIAt xAI, our vision is to develop AI systems that deeply comprehend the universe and assist humanity in its quest for understanding. Our team is a close-knit, highly driven group committed to engineering excellence. We welcome individuals who relish challenges and thrive on curiosity. Operating within a flat organizational structure, we expect all employees to be hands-on contributors to our mission. Proactive leadership is recognized, and a strong work ethic combined with exceptional prioritization skills is essential. Effective communication is crucial, as employees must be able to share knowledge clearly and precisely with colleagues.ROLE OVERVIEW:Join our Grok Voice Model team to engineer the leading voice AI technology. We aim to facilitate seamless, natural, low-latency spoken interactions that are expressive, multilingual, and reliable across devices and real-time applications. We manage the entire training pipeline, encompassing extensive data curation, high-quality audio processing, cutting-edge speech-language pre-training, and rigorous post-training to maximize quality, speed, and stability.Our aspiration is to make conversing with AI feel like engaging with the most charming, knowledgeable, and kind individual imaginable. We are in search of exceptionally intelligent, execution-focused engineers to help us achieve this goal.

Join SpaceX as a Member of Technical Staff, where you will play a crucial role in supporting government initiatives and projects that require top-secret clearance. Your expertise will contribute to the development of cutting-edge technologies that are transforming space exploration and enabling humanity's future in space.

xai is seeking a Technical Staff Member focused on Post-Training and Reinforcement Learning at its Palo Alto, CA location. This position centers on advancing AI technology through hands-on project work and collaboration. Role overview This role involves contributing to projects that explore and extend the capabilities of AI systems. The work emphasizes post-training techniques and reinforcement learning methods, supporting the ongoing development of advanced solutions. Collaboration Teamwork is central to this position. You will work closely with colleagues to share ideas, refine approaches, and help shape the next generation of AI systems at xai.

Join our innovative team at xai as a Member of the Technical Staff for our X Core Product. In this pivotal role, you will leverage your expertise to drive cutting-edge solutions that enhance product performance and user experience. Collaborate with cross-functional teams to design, implement, and optimize system architectures while contributing to the development of next-generation technologies.

About xAIAt xAI, we are on a mission to develop cutting-edge AI systems that not only comprehend the complexities of the universe but also empower humanity in its quest for knowledge. Our team is small yet highly driven, dedicated to achieving engineering excellence. We welcome individuals who relish challenges and have an insatiable curiosity. Operating with a flat organizational structure, we encourage hands-on contributions from all team members towards our collective mission. Leadership is earned through initiative and consistent high performance, making work ethic and prioritization crucial. Strong communication skills are essential, as sharing knowledge effectively with teammates is a key expectation.About the RolexAI is on the lookout for skilled software engineers to construct robust data pipelines, develop comprehensive evaluation frameworks for benchmarking large language models (LLMs), and create automation solutions that enhance the productivity of our researchers and engineers.Focus AreasDeveloping and maintaining frameworks for agent, data, and model evaluation tasks.Creating environments for AI agents.Designing tools to automate common workflows.Enhancing alerts, metrics, and error handling for large-scale reinforcement learning tasks.Refactoring existing agent, data, evaluation, and training frameworks for improved modularity.Establishing operational procedures and coding standards to facilitate the transition from small-scale experiments to large-scale reinforcement learning training.Implementing unit tests and CI/CD frameworks to support rapid development cycles.Ideal ExperienceProven experience in building and maintaining frameworks utilized by multiple engineers.Expertise in creating high-performance sandboxes, virtual machines, and simulations.Experience in developing full-stack applications for workflow automation and data visualization.Capability in rapidly iterating research into production cycles.Knowledge in test automation and CI/CD practices.Typical Challenges You Will EncounterExploring new agentic model capabilities...

Join Our Team at SimileAt Simile, we are revolutionizing decision-making in society by providing AI simulations that accurately model human behavior. Just as pilots and surgeons rely on simulations for training, we believe that businesses deserve the same rigor when making high-stakes decisions.Our groundbreaking work has led to the creation of the first AI simulation of society, featuring generative agents that reflect real human experiences. Backed by $100 million from top investors, including Index Ventures and renowned AI experts, we are on a mission to predict human behavior with unparalleled accuracy.The RoleAs an Applied Research Engineer and Member of Technical Staff (MTS), you will be integral in refining our models of human behavior. With a strong emphasis on scientific rigor, you will participate in the entire research cycle—from designing experiments to implementing them in production systems that influence real-world decisions.Your Responsibilities Will Include:Data Insight Extraction: Analyze extensive proprietary datasets, including unstructured interviews and behavioral data, to uncover meaningful insights.Hardware Proficiency: Develop and optimize algorithms for cutting-edge NVIDIA hardware, conducting experiments that inform our model training.Scientific Leadership: Design thorough evaluations that validate our behavioral simulations against industry standards.Pushing Boundaries: Engage with the latest research in simulation and AI, continuously enhancing our methodologies and documentation.

Join xAI as a Member of the Technical Staff specializing in Inference Engineering. Our mission is to engineer cutting-edge AI systems that enhance humanity's understanding of the universe. We are a dynamic, compact team dedicated to excellence, where each member is encouraged to take initiative and contribute significantly to our objectives. The ideal candidate will thrive in a collaborative environment, showcasing their expertise in optimizing model inference and developing robust systems capable of serving billions of users. If you are passionate about pushing the boundaries of AI technology and enjoy tackling complex challenges, we want you on our team.

Join our innovative team at Elorian AI Inc. as we spearhead the development of cutting-edge visual intelligence solutions. We are on the lookout for exceptional researchers and engineers who are passionate about advancing the field of artificial intelligence. If you are committed to excellence and thrive in a dynamic environment, we would love to hear from you.

About UsAt Vinci, we are revolutionizing simulation technology by combining a robust foundation model for physics with GPU-native solvers, achieving unmatched speed and accuracy in simulations. Our innovative approach eliminates the need for meshing and approximations, enabling engineers to execute thousands of simulations effortlessly and redefining the design and optimization of complex physical systems.Our dedicated teams utilize high-performance computing, secure networking, and seamless cloud integrations to expedite development processes. We are in search of a pragmatic full-stack engineer who is adept in managing customer-facing UIs, backend services, and native C++ integrations. This role demands a proactive individual who can deliver features end-to-end and take full ownership of customer interactions.Role SummaryThis hands-on full-stack position involves building and maintaining Python/gRPC services that interface with our C++ engines. You will be responsible for implementing UI enhancements for customer and internal applications and ensuring that features are accessible and user-friendly. The ideal candidate should be comfortable traversing the technology stack, proficient in delivering production-grade services, and eager to improve product usability and security for our customers.What You’ll DoDesign, develop, and manage Python-based microservices and gRPC APIs that expose native C++ engines and simulation/inference workflows.Execute small-to-medium UI modifications and collaborate with product/UX teams on customer-facing React applications (TypeScript/JS, HTML/CSS), from resolving bugs to adding new functionalities.Implement comprehensive application logic: validate requests, orchestrate jobs, ensure retries/idempotency, maintain transactional integrity, and develop SDKs/APIs for customers.Assist in designing and maintaining distributed systems: job partitioning, managing backpressure, implementing retries, ensuring observability, and autoscaling for services coordinating native compute resources.Debug and analyze performance across the stack — from frontend responsiveness and network requests to Python runtime and native C++ performance hotspots.Establish CI/CD pipelines and automated tests (unit, integration, end-to-end) covering backend, frontend, and native components.Engage in on-call rotations, incident management, and post-mortem analysis; maintain operational documentation and dashboards.Collaborate with product, QA, infrastructure, and customer success teams to ensure features are useful, secure, and thoroughly documented.Mentor fellow team members and contribute to code reviews and knowledge sharing.

Join SpaceX as a Platform Engineer, where you will contribute to the development and maintenance of our cutting-edge technology platforms. This role entails working with a talented team to build robust systems that support our missions in space exploration. Your expertise and innovation can help us push the boundaries of what is possible.

Join our innovative team at xai as a Member of Technical Staff specializing in Web Foundations. In this role, you will collaborate with cross-functional teams to develop and enhance our web infrastructure, ensuring high performance and scalability. You will have the opportunity to leverage cutting-edge technologies to build and maintain robust web applications that serve our global user base.

About the Role SpaceX is hiring a Technical Staff Member to support projects in the Government sector at our Palo Alto, CA location. This role involves hands-on work designing, developing, and implementing technical solutions for government clients. Projects center on aerospace technology and support SpaceX’s mission to make life multi-planetary. What You Will Do Create and deliver technical solutions tailored to government requirements Work closely with a skilled team to address complex engineering challenges Contribute to projects that push the boundaries of aerospace technology Location Palo Alto, CA

About MithrilMithril is revolutionizing AI infrastructure, making GPU computing more accessible and affordable for leading enterprises, AI startups, and the research community, including notable collaborators like LG AI Research, Saronic, and the Broad Institute. Founded by a visionary ex-Google DeepMind researcher and a Stanford CS PhD, Mithril has successfully raised $80 million in seed and Series A funding, backed by prestigious investors such as Sequoia Capital and Lightspeed Venture Partners. Our platform's revenue has surged over 6x in the past year, and we are proud to be recognized as the 8th Most Innovative Company in Artificial Intelligence by Fast Company for 2026.We are at a pivotal moment, transitioning from bare-metal operations to a cloud-native, multi-provider platform distinguished by a flexible auction model. Joining us now means being part of the foundational phase of our platform's development.About the OpportunityAs a Software Engineer on the Consumption Team, you will engage with Mithril's three core engineering domains — Consumption (developer-facing product, billing, and API surface), Platform (orchestration and marketplace engine), and Supply (cloud provider integrations and capacity management). You will take ownership of critical components, delivering features that directly impact revenue and support mission-critical customer operations.This role is uniquely diverse, allowing you to navigate backend systems, marketplace logic, and customer-facing interfaces, giving you firsthand insight into the architectural decisions that will shape Mithril's scalability.What Sets This Role ApartUnlike typical early-stage engineering positions in infrastructure, which often focus narrowly on either systems or product, at Mithril, you will span both areas. You'll develop the orchestration engine that manages GPU capacity across multiple providers while also enhancing the developer interfaces that customers utilize to reserve and consume that capacity effectively.The systems you create will manage real financial transactions and workloads, addressing market dynamics such as spot auctions, reservation pricing, and capacity allocation across a diverse supply base. If you're eager to explore how GPU infrastructure markets operate and contribute to the systems that underpin them, this is the role for you.