Senior Software Engineer, RL Post-Training Frameworks

NVIDIA Gruppe; Santa Clara (CA); Hybrid; USD 184,000 - 357,000; Full time

Benefits offered by this job

Equity

Job summary

NVIDIA seeks an engineer to architect and scale RL post-training infrastructure from experimentation on a single GPU to production across thousands of nodes. You will optimize training-inference loops on GPUs, CPUs, and LPUs while improving open-source RL frameworks and partnering with cross-team groups.

The role requires expertise in distributed systems, Python and C/C++, and experience delivering production-grade runtime frameworks at large AI labs or hyperscalers. Hybrid work is supported.

Qualifications

• MS or PhD in Computer Science, Computer Engineering, or a related field (or equivalent experience)
• 5+ years of professional experience in distributed systems, high-performance computing, deep learning infrastructure, or ML systems engineering
• Strong proficiency in Python and C/C++
• Demonstrated experience building or contributing to large-scale distributed systems or runtime frameworks in production at a frontier AI lab, hyperscaler, or major technology company
• Strong verbal and written communication skills and the ability to collaborate across organizational and geographic boundaries

Responsibilities

• Architect and build RL post-training infrastructure that scales from a single GPU to thousands of nodes
• Tune RL training-inference-rollout loops for performance on GPUs, CPUs, and LPUs
• Improve performance and usability of open-source RL frameworks
• Collaborate with NVIDIA teams (networking, math libraries, compilers) and hardware teams to enable next-gen post-training workloads

Skills

Python

C/C++

Distributed systems

Communication

Education

MS or PhD in CS/CE

Tools

Kubernetes

PyTorch

Ray

NCCL

Job description

What you will be doing:

You will architect and build RL post-training infrastructure that scales efficiently from experimentation on a single GPU to production across thousands of nodes. This means tuning RL training-inference-rollout loops on GPUs, CPUs, and LPUs for performance where it matters, contributing to and improving the performance and usability of open-source RL frameworks, and partnering with the teams who own them. The role also spans fault tolerance, elastic scaling, and fast restarts so long-running distributed training jobs survive failures, stragglers, and resource contention.

Beyond GPU-accelerated training, this work includes partnering with teams building CPU-driven rollout workloads, including tool-use, code execution, and agentic environments, supplying the systems and framework engineering needed to run them efficiently alongside GPU- or LPU-accelerated generation and GPU-accelerated training. It also means advocating for researcher and partner needs with NVIDIA’s networking, math library, and compiler teams so the capabilities RL workloads require get prioritized and delivered, and working with hardware teams to take advantage of next-generation hardware capabilities in post-training workloads.

What we need to see:

• MS or PhD in Computer Science, Computer Engineering, or a related field (or equivalent experience)
• 5+ years of professional experience in distributed systems, high-performance computing, deep learning infrastructure, or ML systems engineering
• Strong proficiency in Python and C/C++
• Demonstrated experience building or contributing to large-scale distributed systems or runtime frameworks in production at a frontier AI lab, hyperscaler, or major technology company
• Strong verbal and written communication skills and the ability to collaborate across organizational and geographic boundaries

Depth in one or more of the following technical areas:

• Reinforcement learning for LLM post-training (RLHF, PPO, GRPO, DPO, reward modeling), including how algorithms map to distributed execution and the systems challenges they create (heterogeneous placement, rollouts, environment execution, resharding between training and generation)
• PyTorch internals, including distributed training primitives (FSDP, tensor parallelism, pipeline parallelism) and their composition
• Kubernetes runtime internals (container lifecycle, pod scheduling, resource quotas, GPU allocation)
• End-to-end distributed systems design (service boundaries, data flows, consistency models, failure modes, recovery approaches)

Experience in any of the following areas is a plus:

• Deep expertise in networking (NCCL, NVLink, InfiniBand), advanced multi-dimensional parallelisms (Megatron-LM, FSDP2, TP/DP/PP, MoE), or memory optimizations (quantization-aware training, mixed precision)
• Experience integrating high-performance inference engines (vLLM, SGLang, TensorRT-LLM) into RL training loops for GPU-accelerated rollout
• Strong background in actor- and task-based distributed programming (Ray, Monarch, or comparable systems)
• Familiarity with multi-turn training, multi-agent co-evolution, or VLM post-training

Ways to stand out from the crowd:

• Open-source contributions to RL post-training or distributed training projects (e.g., VeRL, Miles, TorchTitan, OpenRLHF, NeMo-Aligner, DeepSpeed-Chat), including significant work on framework internals where applicable
• Kubernetes work beyond routine operations (custom operators, GPU device plugins, or scheduling contributions)
• Direct experience operating frontier-scale training (RL post-training at thousands of GPUs and/or large-scale LLM or multimodal pre-training)
• Hands-on experience with production distributed failures at scale (stragglers, resource contention, hardware faults)

Widely considered to be one of the technology world’s most desirable employers, NVIDIA offers highly competitive salaries and a comprehensive benefits package. As you plan your future, see what we can offer to you and your family www.nvidiabenefits.com/

#LI-Hybrid

Your base salary will be determined based on your location, experience, and the pay of employees in similar positions. The base salary range is 184,000 USD - 287,500 USD for Level 4, and 224,000 USD - 356,500 USD for Level 5.

You will also be eligible for equity and benefits.

Applications for this job will be accepted at least until August 25, 2026.

This posting is for an existing vacancy.

NVIDIA uses AI tools in its recruiting processes.

NVIDIA is committed to fostering an inclusive work environment and proud to be an equal opportunity employer. As we highly value diversity in our current and future employees, we do not discriminate (including in our hiring and promotion practices) on the basis of race, religion, color, national origin, gender, gender expression, sexual orientation, age, marital status, veteran status, disability status or any other characteristic protected by law.