Sr Software Dev Engineer, Stores Foundational AI -SFAI

We're building a foundational LLM for Amazon Stores that fuses general world knowledge with Amazon e-commerce domain knowledge to provide new and improved shopping experiences for our customers. We 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! Key job responsibilities In this role you will leverage your engineering background and expertise to help develop generative AI for shopping. As a Senior Software Development Engineer, you will: Architect and build scalable ML infrastructure that powers the training and deployment of large language models—directly shaping the future of AI-driven shopping experiences for all Amazon customers Drive technical innovation by designing experimentation frameworks and tooling that accelerate breakthrough insights, enabling scientists and engineers to iterate faster and smarter Lead cross-functional initiatives partnering with applied scientists and engineering teams to translate frontier research into production systems that delight customers Mentor and elevate the team through technical leadership, code reviews, and architectural guidance—raising the bar for engineering excellence across the organization Own impactful projects end-to-end across diverse technologies—from distributed computing and ML operations to prompt engineering—while navigating ambiguity and making strategic trade-offs that balance innovation with delivery A day in the life On any given day, you may work on: 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 Mentor engineers and contribute to system design and long-term technical roadmap Minimum qualifications - 5+ years of non-internship professional software development experience - 5+ years of programming with at least one software programming language experience - 4+ years of leading design or architecture (design patterns, reliability and scaling) of new and existing systems experience - Experience as a mentor, tech lead or leading an engineering team - Demonstrated ability to drive technical direction and influence engineering decisions across teams Preferred qualifications - Knowledge of ML frameworks including JAX, PyTorch, vLLM, SGLang, Dynamo, TorchXLA, and TensorRT - Knowledge of Machine Learning and LLM fundamentals, including transformer architecture, training/inference lifecycles, and optimization techniques - Experience with distributed systems, big data technologies, and machine learning infrastructure Amazon is an equal opportunity employer and does not discriminate on the basis of protected veteran status, disability, or other legally protected status. Los Angeles County applicants: Job duties for this position include: work safely and cooperatively with other employees, supervisors, and staff; adhere to standards of excellence despite stressful conditions; communicate effectively and respectfully with employees, supervisors, and staff to ensure exceptional customer service; and follow all federal, state, and local laws and Company policies. Criminal history may have a direct, adverse, and negative relationship with some of the material job duties of this position. These include the duties and responsibilities listed above, as well as the abilities to adhere to company policies, exercise sound judgment, effectively manage stress and work safely and respectfully with others, exhibit trustworthiness and professionalism, and safeguard business operations and the Company’s reputation. Pursuant to the Los Angeles County Fair Chance Ordinance, we will consider for employment qualified applicants with arrest and conviction records. 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 https://amazon.jobs/content/en/how-we-hire/accommodations for more information. If the country/region you’re applying in isn’t listed, please contact your Recruiting Partner. The base salary range for this position is listed below. Your Amazon package will include sign-on payments and restricted stock units (RSUs). Final compensation will be determined based on factors including experience, qualifications, and location. 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. Learn more about our benefits at https://amazon.jobs/en/benefits . USA, CA, Palo Alto - 193,300.00 - 261,500.00 USD annually USA, WA, Seattle - 168,100.00 - 227,400.00 USD annually