AI Infrastructure Software Engineer — Cosmoslab

NVIDIA NVIDIA · Semiconductors · Beijing, China +2

NVIDIA's Cosmos Lab Infra team is seeking an AI Infrastructure Software Engineer to build and improve training infrastructure for Physical AI world foundation models. This role involves creating and implementing training infrastructure for pre-training, SFT, and RL post-training, including framework and control plane development, pipeline optimization, inference and evaluation stack development, and integration of simulation/robotics environments. The engineer will also focus on distributed training backends, system reliability, and root cause analysis of failures.

What you'd actually do

  1. Create and implement the training infrastructure spanning pre-training, SFT, and RL post-training for Physical AI world foundation models. The work involves the framework and a comprehensive control plane across clusters to coordinate workloads efficiently.
  2. Develop and improve the pre-training and SFT pipelines — large-scale data loading, distributed training, and checkpointing — to achieve high throughput and scalability.
  3. Develop and improve the inference and evaluation stack, including the inference engine, inference/generation pipelines (which also support RL rollout), and evaluation pipelines. Use methods like continuous batching and KV-cache management to achieve high throughput and low latency.
  4. Build and improve the effective interaction and data flow among the RL system's roles (policy, rollout, reward, simulation) while investigating system-level optimization opportunities.
  5. Integrate and orchestrate simulation and robotics environments as RL environments — driving the simulation↔rollout↔training loop at scale.

Skills

Required

  • Python
  • software engineering practices
  • testing
  • defensive programming
  • version control
  • CI
  • debugging
  • triage skills
  • large-scale distributed systems
  • AI training infrastructure
  • AI inference infrastructure

Nice to have

  • RL post-training infrastructure
  • PPO/GRPO/DPO pipelines
  • rollout engines
  • asynchronous RL
  • large-scale production-grade pre-training/SFT infrastructure
  • integrating simulation/robotics environments
  • vectorized environments
  • sim-to-real workflows
  • DL framework internals
  • PyTorch (FSDP/DTensor)
  • Megatron
  • distributed training optimization
  • C/C++/CUDA
  • custom kernels

What the JD emphasized

  • 5+ years developing software infrastructure for large-scale AI or distributed systems
  • Proven track record building and scaling large-scale distributed systems, ideally distributed training or inference.
  • Hands-on experience with AI training and/or inference infrastructure — RL/post-training, training frameworks, or inference serving.

Other signals

  • large-scale AI training infrastructure
  • distributed training
  • RL infrastructure