Senior AI Infrastructure Engineer - Training Platform

As a Software Engineer on the Machine Learning Infrastructure team, you will build the "Operating System" for our large-scale GPU clusters. You will architect a high-performance training platform that handles the immense complexity of multi-thousand GPU workloads, ensuring every cycle is used efficiently. Your work directly determines the velocity at which our researchers can train and iterate on the world’s most advanced models. The ideal candidate is a systems expert who thrives on solving the orchestration, networking, and reliability challenges that emerge at massive scale. You will partner closely with researchers to build a seamless, resilient environment that transforms raw compute into breakthrough AI. You will: - Architect and scale a multi-tenant orchestration layer that abstracts away the complexity of GPU clusters, ensuring high utilization and seamless job recovery. - Design and implement scheduling primitives to optimize the lifecycle of training jobs. - Develop deep observability and automated health-checking into the training stack to proactively identify and isolate hardware failures - Evaluate and integrate emerging technologies in the CNCF and AI ecosystem (e.g. Ray, Kueue), making data-driven build vs. buy decisions that balance velocity with long-term maintainability. - Work closely with Finance and Procurement teams to drive our capacity planning process. - Participate in our team’s on call process to ensure the availability of our services. - Own projects end-to-end, from requirements, scoping, design, to implementation, in a highly collaborative and cross-functional environment. Ideally you'd have: - 5+ years of experience in backend or infrastructure engineering, with at least 2 years focused on orchestrating ML workloads at scale (100+ GPU nodes). - Strong programming skills in one or more languages (e.g. Python, Go, Rust, C++) - Experience with complex compute management systems that cover queueing, quotas, preemption, and gang scheduling. - Experience with distributed training infrastructure, such as EFA, Infiniband, and topology-aware scheduling. - Experience with distributed storage systems (e.g. Lustre, S3) as they relate to training throughput - Expert-level knowledge of Kubernetes internals (Custom Resources, Operators, Admission Controllers) and how they interact with device plugins for specialized hardware. - Familiarity with cloud infrastructure (AWS, GCP) and infrastructure as code (e.g., Terraform). - Proven ability to solve complex problems and work independently in fast-moving environments. Nice to haves: - Experience with distributed training techniques such as DeepSpeed, FSDP, etc. - Experience with the NVIDIA software and hardware stack (CUDA, NCCL) - Experience with PyTorch - Familiarity with post-training algorithms such as GRPO, and with Reinforcement Learning Compensation packages at Scale for eligible roles include base salary, equity, and benefits. The range displayed on each job posting reflects the minimum and maximum target for new hire salaries for the position and may be inclusive of several career levels at Scale; it will be determined during the interview process based on work location and additional factors, including job-related skills, experience, qualifications, interview performance, and relevant education or training. Scale employees in eligible roles are also granted equity based compensation, subject to Board of Director approval. Your recruiter can share more about the specific salary range for your preferred location during the hiring process, and confirm whether the hired role will be eligible for equity grant. You'll also receive benefits including, but not limited to: comprehensive health, dental and vision coverage, retirement benefits, a learning and development stipend, and generous PTO. Additionally, this role may be eligible for additional benefits such as a commuter stipend. Please reference the job posting's subtitle for where this position will be located. For pay transparency purposes, the base salary range for this full-time position in the locations of San Francisco, New York, Seattle is: $216,000—$270,000 USD PLEASE NOTE: Our policy requires a 90-day waiting period before reconsidering candidates for the same role. This allows us to ensure a fair and thorough evaluation of all applicants. About Us: At Scale, our mission is to develop reliable AI systems for the world's most important decisions. Our products provide the high-quality data and full-stack technologies that power the world's leading models, and help enterprises and governments build, deploy, and oversee AI applications that deliver real impact. We work closely with industry leaders like Meta, Ernst & Young, Mayo Clinic, Time Inc., the Government of Qatar, and U.S. government agencies including the Army and Air Force. We are expanding our team to accelerate the development of AI applications. We believe that everyone should