Software Dev Engineer II, Stores Foundational AI -SFAI

Software Dev Engineer II, Stores Foundational AI
-SFAI

Job :  |  Services LLC

We’re working to improve shopping on Amazon using the capabilities of large language models (LLM), and are searching for pioneers who are passionate about technology, innovation, and customer experience, and are ready to make a lasting impact on the industry. You'll be working with talented scientists and engineers to innovate on behalf of our customers. If you're fired up about being part of a dynamic, driven team, then this is your moment to join us on this exciting journey!

• Design and implementation of a stable and efficient training system for model training and reinforcement learning that scales to various model sizes and architectures.
• Collaborate with applied scientists and engineers to improve training efficiency and reliability that accelerates innovation.
• Design and implement scalable data infrastructure that handles Amazon-scale data ingestion, processing, and delivery across different training and evaluation stages.
• Quickly learn and adopt state-of-the-art technologies and algorithms in the field of generative AI.

• Design and build end-to-end RL post-training pipelines (rollout → reward → optimization) at cluster scale.
• Improve RL training stability (PPO / GRPO / RLOO) by monitoring and tuning key metrics such as reward, KL divergence, and policy stability.
• Optimize RL post-training efficiency (GPU utilization, batching, sequence packing, async rollouts).
• Partner with research scientists to translate new RL algorithms into scalable, production-ready systems.
• Profile and eliminate bottlenecks across compute, networking, and storage.
• Build observability systems for training dynamics, system health, and experiment tracking.
• Collaborate cross-functionally to run experiments, iterate quickly, and unblock research progress.
• Contribute to system design and long-term technical roadmap.

The SFAI Training Infrastructure team builds a unified platform for large-scale LLM training, supporting the full lifecycle from pretraining to fine-tuning and RL post-training. We focus on solving hard system challenges at the intersection of distributed systems and machine learning, building a platform that is scalable, reliable, efficient, and simple and unified. The platform provides a consistent, config-driven interface across models and workflows.

• 3+ years of non-internship professional software development experience.
• 2+ years of non-internship design or architecture of new and existing systems experience (design patterns, reliability and scaling).
• Experience programming with at least one software programming language.
• Knowledge of machine learning and LLM fundamentals, including transformer architecture, training/inference life cycles, and optimization techniques.

• Knowledge of ML frameworks including JAX, PyTorch, vLLM, SGLang, Dynamo, Torch
  
  XLA, and Tensor
  
  RT.
• Knowledge of system performance, memory management, and parallel computing principles.
• Experience with CUDA/C++/kernel development.

Amazon also offers comprehensive benefits including health insurance (medical, dental, vision, prescription, Basic Life & AD&D insurance and option for Supplemental life plans, EAP, Mental Health Support, Medical Advice Line, Flexible Spending Accounts, Adoption and Surrogacy Reimbursement coverage), 401(k) matching, paid time off, and parental leave.

Amazon is an equal opportunity employer and does not discriminate on the basis of protected veteran status, disability, or other legally protected status. Our inclusive culture empowers Amazonians to deliver the best results for our customers. If you have a disability and need a workplace accommodation or adjustment during the application and hiring process, including support for the interview or onboarding process, please visit (Use the "Apply for this Job" box below).

for more information. If the country/region you’re applying in isn’t listed, please contact your Recruiting Partner.

Seattle, WA, USA – annual salary range: 143,700 – 194,400 USD.