Senior Software Engineer, AI Runtime

P-1428 At the company, we are passionate about enabling data teams to solve the world's toughest problems — from making the next mode of transportation a reality to accelerating the development of medical breakthroughs. We do this by building and running the world's best data and AI infrastructure platform so our customers can use deep data insights to improve their business. Training and customizing state‑of‑the‑art AI models is one of the most demanding workloads in computing, and it sits at the heart of the company’s Mosaic AI mission. AI Runtime (AIR) is our managed platform for large‑scale GPU training and fine‑tuning. It gives customers on‑demand access to fleets of the latest accelerators and a serverless experience that hides the complexity of provisioning, scheduling, and orchestrating multi‑node jobs, with the resilience to keep training running for days or weeks across thousands of GPUs. AIR powers the full spectrum of custom training, from fine‑tuning open models to pre‑training frontier‑scale foundation models, for some of the most sophisticated AI teams in the world. As a Senior Software Engineer for AI Runtime, you will play a critical role in building and scaling the systems that make large‑scale training fast, reliable, and effortless. You will drive the architecture and evolution of the managed GPU training stack, spanning scheduling and capacity, distributed training performance, fault tolerance, and the developer experience of launching and operating jobs at scale. Beyond hands‑on contributions to core systems, you will help shape the technical direction for AIR, mentor other engineers, partner across product, research, and platform teams, and contribute to the initiatives that expand the technical and business impact of custom training at the company. Impact you will have: Drive the architecture and evolution of AIR’s managed GPU training platform, delivering scalable, high‑throughput, and resilient training across fleets that span thousands of accelerators. Solve the hardest problems in large‑scale training, including multi‑node orchestration, distributed parallelism strategies, GPU scheduling and dynamic routing, high‑throughput data loading, and checkpoint and restore for very long‑running jobs. Push GPU efficiency and training performance, raising utilization (such as model FLOPs utilization and end‑to‑end throughput) and lowering cost per training run across diverse model architectures and hardware generations. Build the resilience and observability foundations that keep multi‑node jobs healthy, detecting and recovering from hardware and software failures with minimal disruption to customers. Partner with product, research, and platform teams to shape the APIs, CLI, and developer experience that make it easy to launch, monitor, and debug production training jobs. Lead end‑to‑end engineering efforts, from design through production rollout, holding a high bar for performance, correctness, and reliability. Make direct, high‑impact contributions to the core systems behind AIR, and help bring up support for the latest accelerators and new regions as the fleet grows. Champion engineering excellence, mentor other engineers through design reviews and technical discussions, and contribute to the company’s technical direction in AI training infrastructure. What we look for: 5+ years of experience building and operating large‑scale distributed systems, with experience in GPU training infrastructure, high‑performance computing, or ML systems. Experience with distributed training frameworks (such as PyTorch, FSDP, DeepSpeed, or Megatron) and the parallelism strategies (data, tensor, pipeline, and sequence parallelism) used to train large models. Strong understanding of training resilience patterns, including checkpointing, failure detection, and automatic recovery for long‑running, multi‑node jobs. Solid grasp of GPU performance fundamentals, including accelerator architecture, high‑speed interconnects (such as NVLink and InfiniBand or RoCE), collective communication, and the bottlenecks that govern training throughput and utilization. Experience building and operating managed, multi‑tenant platform products in the cloud, with clear SLAs and SLOs for availability, performance, and reliability. Strong foundation in algorithms, data structures, and system design as applied to performance‑sensitive, large‑scale distributed systems. Proven ability to deliver technically complex, high‑impact initiatives that create clear customer or business value. Strong communication skills and the ability to collaborate across product, research, and infrastructure teams in a fast‑moving environment. Customer‑focused mindset with the ability to align implementation details with product goals, and a passion for mentoring engineers and fostering technical excellence. BS in Computer Science or a related field (MS or PhD preferred). Pay Range Transparency The company is committed to fair and equitable compensation practices. The pay range(s) for this role is listed below and represents the expected salary range for non‑commissionable roles or on‑target earnings for commissionable roles. Actual compensation packages are based on several factors that are unique to each candidate, including but not limited to job‑related skills, depth of experience, relevant certifications and training, and specific work location. Based on the factors above, the company anticipates utilizing the full width of the range. The total compensation package for this position may also include eligibility for annual performance bonus, equity, and the benefits listed above. For more information regarding which range your location is in visit our page here. Local Pay Range $160,000 — $225,000 USD #J-18808-Ljbffr