Model Behavior Engineer in United States

About Us: AI needs a new infrastructure layer. We're building it at Modal. Every era of computing brought new workloads that previous infrastructure couldn't support: mainframes, databases, and the cloud. Each time, the company that rebuilt the layer underneath defined the decade. AI is no different, except it touches everything instead of one slice, and the window to build the layer underneath it is open right now. Our customers include category-defining companies like Lovable , Ramp , Cognition, DoorDash, and Suno. They rely on Modal for instant GPU access, sub-second container starts, and native storage, so it's simple to serve low-latency inference, fine-tune models, and access production-ready sandboxes at scale. We recently raised a $355M Series C at a $4.65B valuation, led by General Catalyst and Redpoint Ventures. We've crossed $300M+ ARR and grown fivefold since September. Our team includes creators of popular open-source projects (e.g., Seaborn , Luig i ), academic researchers, international olympiad medalists, and experienced engineering and product leaders with decades of experience. The Role: We're looking for a Detection & Response Engineer to build the systems that help us identify, investigate, and respond to threats across our platform. This is an engineering role focused on automation. You'll build detections, investigation tooling, and response capabilities that scale with our infrastructure, using AI where it meaningfully improves signal, investigation speed, and operational effectiveness. You'll work closely with infrastructure, platform, and security engineers to ensure every incident makes the platform more resilient. What You'll Work On: Detection Engineering Design and build high-fidelity detections for attacks, abuse, and anomalous behavior across our infrastructure and production systems Continuously improve detections based on telemetry, threat intelligence, and lessons learned from incidents Improve visibility across cloud infrastruc

ABOUT BASETEN Baseten powers mission-critical inference for the world's most dynamic AI companies, like Cursor, Notion, OpenEvidence, Abridge, Clay, Gamma, and Writer. By uniting applied AI research, flexible infrastructure, and seamless developer tooling, we enable companies operating at the frontier of AI to bring cutting-edge models into production. We're growing quickly and recently raised our $1.5B Series F , led by Altimeter Capital, Conviction Partners, and Spark Capital. Join us and help build the platform engineers turn to ship AI products. THE ROLE The largest, most demanding enterprises run on Baseten, and they bring exacting requirements for how people, services, and agents access the platform. This is the founding role for our identity and authorization team within enterprise engineering. You'll own the identity and access layer of the Baseten platform: the authorization model, credential systems, and admin experiences that enterprise IT teams use to govern access for organizations like Harvey, HubSpot, and Notion. You'll design and build Baseten's fine-grained authorization system from the ground up to support the workflows customers depend on today while giving them cleaner, more precise ways to manage access as the platform grows. Authorization at Baseten requires low-latency permission checks at high request volume, consistent contracts and behaviors across the product suite, and strong security guarantees for mission-critical, highly regulated workloads. EXAMPLE INITIATIVES Recent and upcoming work in this area: Fine-grained authorization for users, service accounts, and agentic workloads: per-resource permissions at the organization, team, and workload scope to support both common workflows and complex enterprise access policies Programmatic authentication allowing high-compliance customers to connect service principles securely via short-lived, workload-based credentials Agent credentials that grant an agent exactly the access it needs for the gi

About the Team: OpenAI’s Hardware organization develops AI-native silicon and system-level solutions for the unique demands of advanced AI workloads. Building on efforts like Jalapeño, the team is developing future generations of AI-native silicon and tightly integrated systems to power the next generation of frontier models. By co-designing chips, systems, tools, and methodologies, the team helps deliver faster, more efficient, and production-ready hardware for OpenAI’s supercomputing platform. Role Overview We are seeking a Package Reliability Engineer to lead reliability engineering for advanced packages used in high-performance AI and computing systems. The primary focus of this role is to assess package level mechanical and thermal reliability risks and apply thermal and mechanical modeling to optimize package design, material selection, and assembly processes. The engineer will also develop reliability test plans with external partners, identify failure mechanisms, perform root-cause analysis, and recommend practical corrective actions. In this role, you will assess package reliability risks from early architecture development through product qualification and high-volume manufacturing. You will work closely with package design, silicon design, system engineering, manufacturing, and ASIC partners to predict package behavior, develop qualification strategies, resolve reliability issues, and improve overall package robustness and lifetime. In this role you will: Lead reliability test plan and assessments for advanced HPC packages, including risk identification, potential failure-mechanism analysis, root-cause investigation, mitigation planning, and corrective-action development. Drive reliability-focused package design optimization based on thermo-mechanical modeling to improve package reliability, power integrity, thermal performance, mechanical robustness, and platform scalability. Develop, validate, and apply package reliability models and lifetime-prediction

About the Team The Scaling team is responsible for the architectural and engineering backbone of OpenAI’s infrastructure. We design and deliver advanced systems that support the deployment and operation of cutting-edge AI models. Our work spans system software, networking, platform architecture, fleet-level monitoring, and performance optimization. About the Role We’re hiring an SW Engineer to enable production workloads and end-to-end testing on new platforms. This role will include creating new test harnesses and platform stress benchmarks, porting existing inference and training workloads to new, sometimes early-access, systems/hardware, analyzing performance and bottlenecks, and characterizing the end-to-end behavior of new systems (compute, comms, storage, control plane, and failure modes). Key Responsibilities Port and validate key inference and training workloads on new platforms/SKUs as they arrive; drive correctness, performance, and stability to an internal readiness bar. Build a suite of benchmarks and stress tests that capture real E2E behavior of our workloads by exercising all aspects of a system, including CPU, GPU, memory subsystem, frontend, scale-up, and scale-out networking (including WAN traffic, NVlink and RDMA collectives), storage, thermals, and any other relevant parts. Deep-dive performance on distributed training/inference: Collective performance and tuning (across NCCL/RCCL and internal libraries) Overlap of compute/communication, kernel-level bottlenecks, memory bandwidth and scheduling effects Create repeatable test harnesses that run in CI / lab environments and produce actionable outputs (pass/fail, performance score, regression detection). Partner with systems + fleet bring-up engineers to ensure the platform is not only stable and performant, but also operationally usable and scalable (containerization, K8s integration, telemetry hooks, failure triage loops). Work cross-functionally with vendors and internal stakeholders by producing

About the Team OpenAI’s Hardware organization develops AI-native silicon and system-level solutions for the unique demands of advanced AI workloads. Building on efforts like Jalapeño, the team is developing future generations of AI-native silicon and tightly integrated systems to power the next generation of frontier models. By co-designing chips, systems, tools, and methodologies, the team helps deliver faster, more efficient, and production-ready hardware for OpenAI’s supercomputing platform. About the Role You will build the low-level device runtime that turns compiled programs into efficient, functional and performant execution on OpenAI’s custom AI accelerator. This software will schedule kernel launches, manage device memory and address spaces, coordinate synchronization, and expose reliable abstractions to higher-level runtimes and frameworks. You will work at the boundary of software and hardware, partnering with compiler, kernel, architecture, verification, and silicon teams to define interfaces and validate behavior. You will also use and improve event-based, cycle-accurate simulation to develop runtime capabilities before silicon is available, diagnose performance and correctness issues, and guide hardware-software co-design. In this role, you will: Design and implement the low-level device runtime for OpenAI custom silicon. Build kernel-launch scheduling, command submission, queueing, dependency tracking, and completion handling. Manage device memory spaces, allocation, virtual-to-physical mappings, data movement, and lifetime across concurrent workloads. Implement synchronization primitives, events, barriers, streams, and ordering guarantees that are correct and efficient. Define clean interfaces between the runtime, drivers, firmware, compiler-generated code, kernels, and higher-level execution systems. Use event-based, cycle-accurate simulators to develop, validate, debug, and performance-tune runtime behavior before and after silicon availability. Di

ABOUT BASETEN Baseten powers mission-critical inference for the world's most dynamic AI companies, like Cursor, Notion, OpenEvidence, Abridge, Clay, Gamma and Writer. By uniting applied AI research, flexible infrastructure, and seamless developer tooling, we enable companies operating at the frontier of AI to bring cutting-edge models into production. We're growing quickly and recently raised our $1.5B Series F , led by Altimeter Capital, Conviction Partners, and Spark Capital. Join us and help build the platform engineers turn to to ship AI products. THE ROLE As a Site Reliability Engineer at Baseten, you'll define and codify the gold standards of day 2 operations for our ML infrastructure platform. You'll envision and build robust systems, processes, automations, and observability tooling that keep our platform reliable at scale — and that empower the broader organization to operate confidently. You'll work closely with engineering, forward-deployed and product teams: learning from recurring failure patterns, turning tribal knowledge into automated mitigations, and raising the operational floor for the entire company. EXAMPLE INITIATIVES You'll work on projects like these as part of the SRE team: Improve Baseten SRE Practices, by instrumenting SLOs and SLIs, improving alerting and observability for all services. Building AI-assisted tooling for incident triage and response. RESPONSIBILITIES Own the reliability of Baseten's multi-cloud Kubernetes infrastructure, including incident response, post-mortems, and remediation tracking. Build and maintain observability infrastructure — metrics, logging, dashboards, and alerting — as code. Author, validate, and improve runbooks for recurring failure patterns, ensuring they're structured for low-context, safe execution. Identify high-frequency failure patterns and convert them into automated mitigations or self-healing automations. Diagnose and resolve runtime issues related to latency, memory behavior, GPU utilization, con

About the Team The Safety Systems team is dedicated to ensuring the safety, robustness, and reliability of AI models and their deployment in the real world. Learn more about OpenAI’s approach to safety. Building on the many years of our practical alignment work and applied safety efforts, Safety Systems addresses emerging safety issues and develops new fundamental solutions to enable the safe deployment of our most advanced models and future AGI, to make AI that is beneficial and trustworthy. About the Role At OpenAI, we're dedicated to advancing artificial intelligence, and we know that creating a secure and reliable platform is vital to our mission. That's why we're seeking a software engineer to help us build out our trust and safety capabilities. In this role, you'll work with our entire engineering team to design and implement systems that detect and prevent abuse, promote user safety, and reduce risk across our platform. You'll be at the forefront of our efforts to ensure that the immense potential of AI is harnessed in a responsible and sustainable manner. Your Responsibilities: Architect, build, and maintain anti-abuse and content moderation infrastructure designed to protect us and end users from unwanted behavior. Work closely with our other engineers and researchers to utilize both industry standard and novel AI techniques to measure, monitor and improve AI models’ alignment to human values. . Diagnose and remediate active incidents on the platform and build new tooling and infrastructure that address the root causes of system failure. You might thrive in this role if: You have built and run production services in a high growth, rapidly scaling environment. You can debug live issues and restore systems quickly. You have worked on content safety, fraud, or abuse, or are motivated and excited to work on present-day (“now-term”) AI safety. You have experience with Python or with modern languages such as C++, Rust, or Go, and are able to quickly ramp up on Py

Firmware Engineer BIOS/UEFI Description - The Firmware Engineer is responsible for ensuring that embedded firmware meets the highest standards of quality, robustness, and long‑term reliability. This role works closely with firmware developers, hardware engineers, architecture teams, QA, and cross‑functional partners to define quality metrics, validate system behavior, improve defect detection, and build processes that prevent regressions. Responsibilities Develop, execute, and maintain comprehensive firmware test plans, including functional, regression, stress, corner-case, and long-duration reliability tests. • • • Evaluates the firmware architecture, design and development plus testing methodologies to create strategy and implement methods to bring increased quality and reliability to the firmware. Reviews firmware code and test plans including functional, regression, stress, corner-case and long-duration reliability tests. Perform root-cause analysis for firmware defects, drive containment, corrective actions, and verification of fixes. Create and manage quality dashboards, KPI, failure rates, and reliability metrics. Evaluate failure modes exposed during design, development, manufacturing and field use; propose design or process improvements to prevent recurrence. Works with product architects, firmware teams, product managers and provides critical guidance, system-level debugging and troubleshooting to various teams, as a Subject Matter Expert. Reviews and evaluates designs and project activities for compliance with systems design and development guidelines and standards; provides tangible feedback to improve product quality and mitigate failure risk. Create and manage quality dashboards , KPIs, failure rates, and reliability metrics. Validate firmware integration with hardware, BIOS/UEFI, EC, micro

Tenstorrent is leading the industry on cutting-edge AI technology, revolutionizing performance expectations, ease of use, and cost efficiency. With AI redefining the computing paradigm, solutions must evolve to unify innovations in software models, compilers, platforms, networking, and semiconductors. Our diverse team of technologists have developed a high performance RISC-V CPU from scratch, and share a passion for AI and a deep desire to build the best AI platform possible. We value collaboration, curiosity, and a commitment to solving hard problems. We are growing our team and looking for contributors of all seniorities. Our Tensix team is building custom AI compute cores, RISC-V CPUs, and chiplet-based architectures for datacenter, edge, and automotive AI. Design Verification Engineers on this team validate compute IP and subsystems and build scalable DV infrastructure to keep verification fast, automated, and production-grade. This role is hybrid, based out of Toronto, ON, Austin, TX or Belgrade, Serbia. We welcome candidates at various experience levels for this role. During the interview process, candidates will be assessed for the appropriate level, and offers will align with that level, which may differ from the one in this posting. Who You Are Experienced in modern verification methodologies with strong SystemVerilog skills and exposure to structured testbench development. Comfortable working from block-level to system-level verification and reasoning about microarchitecture behavior from specs and waveforms. Proficient in Linux environments with Python, or Bash scripting for automate builds, parse logs, manage CI pipelines. Skilled in coverage-driven verification and confident debugging across RTL, testbench, and workload scenarios. Motivated by AI hardware and eager to learn verification strategies for new architectures and domains. What We Need Contribute to verification of Tensix IP and subsystems from early planning through tape-out, owning cov

ABOUT THE TEAM The AI Foundations Team at Mural is pioneering how generative AI transforms visual collaboration and decision-making. We’re a remote-first group of engineers, designers, and product thinkers focused on helping teams work together more effectively. Our goal isn’t to replace human creativity. It’s to amplify it, building AI that enhances how people align, communicate, and make decisions visually. YOUR MISSION You will design and build the core AI systems and platforms that enable Mural’s next wave of agentic, AI-driven collaboration experiences. Rather than building isolated AI features, you’ll work on the core backend systems that power Mural’s agent platform, including agent orchestration, durable execution, contextual memory, tool integration, observability, and evaluation. Your work will enable intelligent agents to reason over product context, act on behalf of users, and operate reliably and safely at scale. Our stack at Mural includes Azure OpenAI, React, Node, MongoDB. WHAT YOU'LL DO Build the core backend systems that power Mural’s agent platform, including orchestration, durable execution, tool execution, memory, observability, and evaluation infrastructure Design scalable services and APIs that allow AI agents to retrieve context, coordinate multi-step workflows, interact with Mural data, and act reliably on behalf of users Develop the agent memory layer, including systems for conversation context, product context, retrieval, summarization, compaction, and long-term context management Create infrastructure to monitor, debug, and improve agent behavior through traces, metrics, feedback loops, and offline evaluation Translate complex, open-ended product needs into clear backend architectures, service boundaries, data models, and implementation plans that align technical capabilities with user value Help define the technical direction for agentic AI at Mural, contributing to long-term architecture and strategy Champion engineering excellence, men

Replit is the agentic software creation platform that enables anyone to build applications using natural language. With millions of users worldwide, Replit is democratizing software development by removing traditional barriers to application creation. About the Role As a Product Engineer, you’ll take emerging ideas from concept to polished experiences. You’ll build sophisticated, intuitive user experiences while working across AI models, agentic workflows, and all parts of web infrastructure to ship complete products. The Goal: Build products that can define major new categories for Replit. You will combine the flexibility of software with the accessibility of presentations, spreadsheets, dashboards, and visual editors, enabling anyone to create powerful, interactive artifacts through natural language. The Audience: We build for the next generation of creators, knowledge workers, and high-leverage teams. Our users should be able to turn an idea, dataset, or business problem into a polished, editable, and shareable product just by themselves. Candidates who thrive here often have the product judgment, technical range, and ownership mindset associated with founders. This is a high-visibility role working closely with product leadership. How we work Structure: We operate as a collective of in-house technical founders, not narrowly specialized engineers. Initiatives are run by lean, autonomous teams built for velocity and technical leverage. Engineers maintain meaningful ownership over technical direction, product quality, and launch success, supported by Product and Design partners. Cadence: We work in focused three-week sprints, shipping quickly, observing real user behavior, and incorporating feedback into each iteration. We value decisive execution, thoughtful experimentation, and the ability to make progress without perfectly defined requirements. What you’ll do Own major product experiences from initial concept through design, implementation, launch, measurement,

Every day, tens of millions of people come to Roblox to explore, create, play, learn, and connect with friends in 3D immersive digital experiences– all created by our global community of developers and creators. At Roblox, we’re building the tools and platform that empower our community to bring any experience that they can imagine to life. Our vision is to reimagine the way people come together, from anywhere in the world, and on any device. We’re on a mission to connect a billion people with optimism and civility, and looking for amazing talent to help us get there. A career at Roblox means you’ll be working to shape the future of human interaction, solving unique technical challenges at scale, and helping to create safer, more civil shared experiences for everyone. From the early days, simulated physics has been the foundation of the way users build in Roblox. Our physics engine enables dynamic environments with emergent behavior making games more immersive and exciting. The Physics team develops Roblox's proprietary distributed physics engine. Our team implements the mathematical models behind our dynamic simulation engine, and ships engine APIs and tools that developers use every day. These models incorporate rigid body dynamics arising from external forces, collisions, and constraints while optimizing for real-time performance. We work on integrating the low level physics solver into the rest of the engine for online gameplay across multiple platforms. You will report to the Physics Environment Engineering Manager. You Will: Innovate and implement powerful physics features that empower Roblox developers to create immersive and dynamic experiences. Drive innovation through research and rapid prototyping , translating new ideas into practical solutions that stand the test of time. Optimize and enhance the robustness and performance of the physics engine and its integrations, ensuring a seamless user experience. Collaborate with internal teams and ext

Every day, tens of millions of people come to Roblox to explore, create, play, learn, and connect with friends in 3D immersive digital experiences– all created by our global community of developers and creators. At Roblox, we’re building the tools and platform that empower our community to bring any experience that they can imagine to life. Our vision is to reimagine the way people come together, from anywhere in the world, and on any device. We’re on a mission to connect a billion people with optimism and civility, and looking for amazing talent to help us get there. A career at Roblox means you’ll be working to shape the future of human interaction, solving unique technical challenges at scale, and helping to create safer, more civil shared experiences for everyone. Why Safety? At Roblox, we strive to connect a billion people with optimism and civility, and the Safety organization’s mission is to become the leader in civil immersive online communities. We systematically detect, remove, and prevent problematic content and behavior, and we make Roblox accounts secure and free from compromise. We cover a broad area of the tech spectrum, including machine learning, classifiers for 3D models, experimentation, automation, detection workflows, and AI-powered text filters. Aligned and partnering with product teams, we use this toolbelt to discover new opportunities, influence and shape the product roadmap and prioritization, build safety products, and measure the impact on our community of users and developers. In doing so, we keep Roblox safe, civil, and inclusive, and we foster positive relationships between people around the world. Why Safety Foundation? Safety Foundation is the infrastructure backbone that powers safety across Roblox. Every piece of content reviewed, every moderation action taken, every safety workflow running anywhere on the platform flows through systems built by this team. We are the platform that other safety teams build on — and right

Every day, tens of millions of people come to Roblox to explore, create, play, learn, and connect with friends in 3D immersive digital experiences– all created by our global community of developers and creators. At Roblox, we’re building the tools and platform that empower our community to bring any experience that they can imagine to life. Our vision is to reimagine the way people come together, from anywhere in the world, and on any device. We’re on a mission to connect a billion people with optimism and civility, and looking for amazing talent to help us get there. A career at Roblox means you’ll be working to shape the future of human interaction, solving unique technical challenges at scale, and helping to create safer, more civil shared experiences for everyone. From the early days, simulated physics has been the foundation of the way users build in Roblox. Our physics engine enables dynamic environments with emergent behavior making games more immersive and exciting. The Physics team develops Roblox's proprietary distributed physics engine. Our team implements the mathematical models behind our dynamic simulation engine, and ships engine APIs and tools that developers use every day. These models incorporate rigid body dynamics arising from external forces, collisions, and constraints while optimizing for real-time performance. We work on integrating the low level physics solver into the rest of the engine for online gameplay across multiple platforms. You will report to the Physics Environment Engineering Manager. You Will: Innovate and implement powerful physics features that empower Roblox developers to create immersive and dynamic experiences. Drive innovation through research and rapid prototyping , translating new ideas into practical solutions that stand the test of time. Optimize and enhance the robustness and performance of the physics engine and its integrations, ensuring a seamless user experience. Collaborate with internal teams and ext

Every day, tens of millions of people come to Roblox to explore, create, play, learn, and connect with friends in 3D immersive digital experiences– all created by our global community of developers and creators. At Roblox, we’re building the tools and platform that empower our community to bring any experience that they can imagine to life. Our vision is to reimagine the way people come together, from anywhere in the world, and on any device. We’re on a mission to connect a billion people with optimism and civility, and looking for amazing talent to help us get there. A career at Roblox means you’ll be working to shape the future of human interaction, solving unique technical challenges at scale, and helping to create safer, more civil shared experiences for everyone. WHY SAFETY? At Roblox, we strive to connect a billion people with optimism and civility, and the Safety organization’s mission is to become the leader in civil immersive online communities. We systematically detect, remove, and prevent problematic accounts, content and behavior, and we make Roblox accounts secure and free from compromise. We cover a broad area of the tech spectrum, including machine learning, classifiers for 3D models, experimentation, automation, detection workflows, and AI-powered text filters. Aligned and partnering with product teams, we use this toolbelt to discover new opportunities, influence and shape the product roadmap and prioritization, build safety products, and measure the impact on our community of users and developers. In doing so, we keep Roblox safe, civil, and inclusive, and we foster positive relationships between people around the world. WHY GAME SAFETY? As a Principal Software Engineer on Game Safety, you’ll work on some of the most challenging problems we face. You will transform our experience safety efforts into a scale-oriented, near-real-time problem, in an adversarial context. This requires an understanding of code, 3D content, player behavior, a