C Engineer in United States

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. The Game Engine team at Roblox works on the systems that power the experiences at the heart of the metaverse. Our code is the technical foundation in our client, editor, and our simulation servers. The Game Engine team is broadly split into departments — Audio-Video-Communication, Avatar, Core AI, Digital Matter, Productivity, and Systems. This position is for the Systems Runtime pod. The Runtime pod builds and maintains the foundational C++ components that power the entire Roblox engine and Studio stack. We own the runtime layer — the performance, efficiency, and usability of the core primitives that every other engineering team relies on. Think of Runtime as the “standard library” and execution engine for Roblox's C++ world. Our ownership centers on three pillars: Concurrency System — our task scheduler and fiber runtime power how work is parallelized across CPU cores, letting teams scale features across platforms while keeping code understandable and debuggable. Memory System — we own the engine's memory allocator stack, tracking pipelines, and observability tooling to make memory behavior predictable and prevent leaks and fragmentation. Profiling and Observability — we build and evolve

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. As a Senior Software Engineer on the Core UI team, you'll take the Roblox App experience to the next level - making it intuitive, reliable, and a joy to use. Our team sits at the intersection of platform engineering and product innovations. You'll work on systems and surfaces used by every Roblox user and creator in every game session. If you care deeply about how software feels - not just how it works - this is the role for you. You Will: Design, build, and own end-to-end development of user-facing features and systems across mobile, desktop, VR, and consoles. Develop robust, extensible systems powering Roblox's core surfaces (Home, Avatar, Search, and more) used by hundreds of millions of users and creators. Create scalable solutions for building high-quality, intuitive, and reliable user interfaces that elevate the overall product experience. Partner with engineering, product, and design teams to deliver cohesive, delightful user experience. You Have: 4+ years of software development experience building large-scale, user-facing applications. Strong expertise in modern frontend technologies, including frameworks like React or similar, component-based architecture, and state management pat

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 Are you passionate about advancing the application of artificial intelligence? We are looking for a Software Engineer focused on ML performance to join our dynamic team. This role is ideal for someone who thrives in a fast-paced startup environment and is eager to make significant contributions to the exciting field of LLM Inference. If you are a backend engineer who thrives on making things faster and is excited about open-source ML models, we look forward to your application. EXAMPLE INITIATIVES You'll get to work on these types of projects as part of our Model Performance team: Baseten Embeddings Inference: The fastest embeddings solution available The Baseten Inference Stack Driving model performance optimization RESPONSIBILITIES Implement, refine, and productionize cutting-edge techniques (quantization, speculative decoding, kv cache reuse, chunked prefill and LoRA) for ML model inference and infrastructure. Deep dive into underlying codebases of TensorRT, PyTorch, TensorRT-LLM, vllm, sglang, CUDA, and other libraries to debug ML performance issues. Apply and scale optimization techniques across a wide range of ML models, particularly large language models. Collaborate with a diverse team to design and implement innovative solutions. Own projects from idea to production. REQUIREMENTS Bachelor's, Master's, or Ph.D. degree in Computer Science, Engineering, Mathematics, or related field. Experience with one

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 an Engineering Manager to lead a team of highly experienced engineers building the infrastructure that powers Modal's serverless GPU platform. This is a hands-on leadership role — expect to split your time between technical contribution and people management depending on what the team needs. You'll set direction, remove blockers, and build a strong engineering culture as your team tackles hard problems in distributed computing, large-scale data handling, and performance optimization. Who You Are You're an experienced engineering leader who stays close to the work and builds alongside your team when it counts. You earn trust through technical depth, not title. You communicate clearly, help strong engineers move fast without cutting corners, and stay calm and pragmatic under pressure. You care as much about how your team gets to an answer as the answ

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 We’re seeking a GPU Kernel Engineer to join our team at the cutting edge of AI acceleration, where your code directly impacts the performance of state-of-the-art machine learning models. As a GPU Kernel Engineer, you'll craft the foundation that powers modern AI workloads, optimizing every microsecond of computation to enable breakthrough applications. You'll work in a fast-paced, intellectually stimulating environment where technical excellence is paramount and your contributions directly influence production systems serving millions of users across numerous products. This role offers exceptional growth potential for engineers passionate about low-level optimization and high-impact systems work. EXAMPLE INITIATIVES You'll get to work on these types of projects as part of our Model Performance team: Baseten Embeddings Inference: The fastest embeddings solution available The Baseten Inference Stack Driving model performance optimization RESPONSIBILITIES Core Engineering Responsibilities Design and implement high-performance GPU kernels for key ML operations, including matrix multiplications, attention mechanisms, and mixture-of-experts routing Write and optimize code using CUDA, PTX assembly, and architecture-specific techniques Apply advanced performance optimization methods such as memory coalescing, warp-level programming, tensor core acceleration, and compute/memory overlap Performance & Innovation Impl

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 OPPORTUNITY We are looking for Senior Software Engineers to join our team. This is a specialized, high-impact role sitting at the intersection of high-performance computing (HPC) and Large Language Model (LLM) engineering. You will not just be building the automated "speedometer and diagnostic" suite for our next-generation AI infrastructure; you will be defining the roadmap, driving key technical decisions, and taking full ownership of the future of this work. RESPONSIBILITIES Benchmarking : Evaluate, run and automate standard LLM quality benchmarks (GSM8K, MMLU) alongside custom performance suites for specific workloads (e.g., long-context window, KV cache reuse, disaggregated serving). DevEx Improvement : Develop and maintain internal GPU-enabled development environments (similar to GitHub Codespaces). You will ensure the team has seamless, high-performance "dev machines" optimized for model experimentation. Tool Development : Build and contribute to open-source tools such as InferenceMAX and genai-bench to automate model evaluation, benchmarking and analysis. System Profiling : Use profilers like PyTorch Profiler, NVIDIA Nsight Systems and py-spy to collect performance profiles, identify bottlenecks, and debug the compute/networking stack. Monitoring & Observability : Develop real-time dashboards and alerts to monitor system health, model startup times, and runtime performance. Continuous Integration : Auto

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. At Baseten, we are building the global operating system for distributed, heterogeneous AI hardware. We believe that as LLM and multi-modal workloads scale, the network is the computer. We are looking for foundational engineers to lead our GPU Networking efforts, making RDMA a first-class building block in our infrastructure and unlocking the next generation of distributed inference optimizations. THE OPPORTUNITY Networking and compute are no longer separate disciplines; they are converging. The massive throughput of H100, B200, and NVL72 architectures enables and demands a new approach where communication is co-optimized alongside computation. We are entering an era where the network is an active accelerator, leveraging smart hardware offloads and direct interconnects to ensure that data movement operates at wire-speed. In this role, you will go beyond network configuration to architect the software fabric that unifies thousands of GPUs into a cohesive operating system. While you will leverage the best of the open-source ecosystem, you won't be limited by it. Where off-the-shelf solutions stop, you will build from scratch, engineering the primitives required to co-optimize communication and compute for Disaggregated Serving, Wide Expert Parallelism (WideEP), and lightening cold starts. WHAT YOU'LL DO Make RDMA First-Class: You will work on integrating RDMA/RoCE/InfiniBand capabilities directly into our inference stack,

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. As a Principal Software Engineer on the Sharing team, you will lead large, multi-team initiatives with long-term technical vision and group-level impact. You will be expected to define and drive the platform-wide strategy powering how millions of users capture, share, and discover content on Roblox. In this role, you will set engineering standards, mentor senior engineers, and serve as a key architect of our long-term technical direction. You Will Drive Strategy & Execution: Own the outcome of complex, business-critical programs spanning several teams, often lasting years. Innovate at Scale: Develop and drive a multi-year technical vision for content creation and sharing, anticipating scale, technology, and business evolution. Elevate Reliability: Lead high-severity incident response across groups; drive durable systemic solutions that improve reliability and velocity. Architect Foundations: Regularly improve shared infrastructure and foundational systems, introducing frameworks that uplift development speed across the organization. Align Teams: Aligns multiple teams on shared technical direction, producing detailed design docs, phased roadmaps, and planning models that balance short an

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. As a Principal Engineer on Content Lifecycle, you will be leading the architecture and design of workflows on Roblox Studio and our platform enabling Creators and AI agents to collaborate at scale by creating, sharing, and managing reusable content. The ideal candidate has C++ and game engine experience, enjoys solving complex software problems and has a passion for mentoring other engineers on the team. We believe that collaborative teams are the future of building one’s imagination on Roblox and you will be designing and building features which unlock that vision. Join us in our mission to make collaboration at scale performant, frictionless, and most of all fun! You Will: Plan and deliver complex technical features E2E in our game engine and in the Roblox Studio that will allow developers to grow in our community Establish the foundational architecture and technical direction that will enable Studio to keep expanding its capabilities Work cross functionally, across teams and technology platforms to deliver high quality and amazing user functionality Lead by example and mentor engineers to implement technological best practices, patterns, and strategies Improve the product quality by fost

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. As a Principal Software Engineer, Audio-Video-Communication team, you'll be in charge of building our upcoming platform to bring multi-modal communication experience - voice chat, 3D audio, and large-scale broadcast, to our users. If you enjoy working on C++ software while building products for the passionate community of Roblox, you'll be right at home within our experienced and growing social team. You will work with our Engineering Managers and Directors within our Engine's team, and will report to our Manager of the Real-Time Communications team. You Will: Build and launch the latest real-time communication platform from the ground up, designed to support billions of users. Employ best programming practices to write code that is efficient, maintainable, and scalable. Play a crucial role in the introduction of high-quality communication features/products on a wide range of devices, from mobile to high-end platforms. Enhance the robustness and performance of existing components Collaborate with engineers across engine and partner teams to create synergistic solutions You Have: Over 8+ years of experience developing and deploying user-facing software products. Successfully deployed a high-

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. The platforms in our Engineering Acceleration org dictate how thousands of Roblox engineers ship, and how every backend service gets built, deployed, and kept reliable at scale. They sit on the critical path for production reliability, developer velocity, and security posture. Reporting to Andrew Swerdlow, you will rethink the entire engineering toolchain from the ground up to be agentic-native, creating a world where AI agents are first-class participants in software development and humans set direction and supervise. This is a unique opportunity to define what modern engineering infrastructure looks like at one of the largest platforms in the world. You will: Reimagine the engineering toolchain as agentic-native, designing the platforms, guardrails, and feedback loops that let AI agents safely drive migrations, validation, and routine operational work. Set a bold technical direction for AI-driven quality, including agent-generated tests, automated coverage of untested paths, intelligent verification, and continuous-deployment workflows. Make software quality and SEV prevention a measurable property of the platform by investing in safe-change mechanisms, automated verification, progressive

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. With Roblox’s daily active users growing at a record pace, we are building the next generation advertising in an immersive metaverse. Our team sits at the core of the Roblox Ads ecosystem, serving billions of impressions while providing the critical infrastructure that connects global brands with our massive community of creators. We are seeking a Principal Software Engineer to drive technical strategy and execution for the Ads Experience team. This team is responsible for the full spectrum of our monetization experience, including Advertiser Experience (Roblox Ads Manager), Brand Experience (Brand Ads & Integrations), and Publisher Experience (Creator Monetization & Commerce). This is a foundational technical challenge beyond standard ad-tech. You will architect the high-scale backbone of our monetization system, driving the technical vision for our Ads Manager, immersive Brand Ads formats, and creator solutions, while pioneering AI integration and balancing a three-sided marketplace economy in real-time. You Will Architect the Roblox Ads Manager: Design and build the end-to-end technical architecture for our flagship advertising platform, ensuring it can handle complex campaign st

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. As a Principal Software Engineer on the Engine DataModel team, you will own and innovate on the foundational components that form the backbone of the Roblox platform. In the Roblox Engine, the DataModel is a tree-like structure that is analogous to a scenegraph in other 3D engines. This role will report to the engineering manager and will be based out of our HQ in San Mateo, CA in a hybrid model 3 days a week (Tuesdays to Thursdays). Our team owns: The core structures and systems are used to build the DataModel and interact with it. The C++ reflection bindings that form the Engine’s Luau API surface and let creators interact with the DataModel. We’ve built custom codegen tooling to generate the C++ for these reflection bindings and other related structures. DataModel serialization … and much more! You will: Develop engine code that performs well for all user-created games on the Roblox platform. Build the core systems and data structures used in the Roblox engine, working with other teams to find universal solutions. Take ownership of projects throughout their full lifecycles. Execute code that performs well on all the devices Roblox supports—from desktop clients to mobile phone clients to

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. As a member of the Infrastructure Foundation Hardware Engineering team, you will play a key role in enabling our mission to deliver a reliable, high-performing, and cost-efficient infrastructure that powers the world’s play. In this specialized role, you will be the technical lead for our GPU and AI accelerator ecosystem. You will be responsible for the full lifecycle of GPU hardware, from initial architectural evaluation and firmware qualification to large-scale fleet integration and performance tuning. You will ensure that Roblox’s massive-scale rendering and ML workloads run on the most optimized and stable hardware possible. You Will: Architect & Prototype: Prototype next-generation GPU-accelerated hardware platforms, ensuring seamless integration between high-density compute nodes, high-speed interconnects (NVLink/PCIe Gen5/6), and system firmware. GPU Optimization: Drive the integration, performance testing, and debugging of GPUs in our fleet, focusing specifically on hardware-level optimizations, driver tuning, and thermal/power management. Validation & Certification: Develop and execute rigorous evaluation and stress-testing strategies for GPU-heavy server platforms to ensur

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. As a Principal Machine Learning Engineer within the Creator Services Machine Intelligence team, you will focus on the research and development of Embodied AI and Behavioral Agents that revolutionize how games are created and played on Roblox. You will bridge the gap between cutting-edge research and massive-scale product application, building agents capable of complex 3D gameplay and unblocking many use cases across Roblox, from automated playtesting to ensure quality, to "ML Players" with human-like movement and strategic reasoning, playing with real players in games. You will work on feature extraction, model training, building validation / RL platform as well as inference set up leveraging methods from imitation learning to reinforcement learning. And you will create generalizable agents that can perceive 3D environments, understand game rules, plan long-term strategies, and execute complex physics-based actions in real-time. You Will: Design and implement foundation models end to end through the feature extraction to inference for embodied agents. Define the long-term roadmap for Game AI and Embodied Intelligence, acting as a technical bar-raiser for code quality and architectural desig