PrincipalEngineer,MLEngineering

We are looking for a Principal Engineer with deep ML engineering expertise to lead the ML and science engineering effort across the AI Platforms organization at AWS. This is a cross-cutting leadership role spanning the full breadth of our ML development platform: data preparation, model evaluation, model deployment and customization, and agentic AI development experience. In this role, you will be responsible for building production-grade 1P agents, designing comprehensive evaluation frameworks (including LLM-as-Judge), creating recommendation systems for model benchmarking and selection, and driving the science-engineering interface to deliver superior developer experiences at AWS scale. You will work closely with world-class science teams to translate innovative research into production systems and establish the technical strategy for ML engineering across the organization. You are not just an architect — you are a hands-on builder who can prototype alongside scientists, write production code, and review designs across multiple teams. You bring a rare combination of ML depth, systems thinking, and the ability to influence without authority at a global scale. Key job responsibilities • Design and build production-grade 1P agent architectures including memory management, prompt optimization, tool use, and agentic orchestration systems • Define and own the evaluation strategy for AI Platforms, including LLM-as-Judge frameworks, automated benchmarking, and model quality assessment pipelines • Build ML-driven recommendation systems for model benchmarking, selection, deployment, and customization from Model Hub • Establish data quality evaluation pipelines and synthetic data generation infrastructure to support model training and fine-tuning at scale • Drive requirements and technical roadmap with the science team; translate research prototypes into engineering specifications and production systems • Define the ML engineering technical strategy across AI Platforms, esta