Responsibilities

• Lead the design and development of the chatbot/agentic AI capability for WeChat and other third-party channels, from concept through production.
• Bring strong ML and LLM/NLP fundamentals to bear on system design — grounding architecture and modeling choices in a deep understanding of the underlying methods.
• Architect and build agentic AI systems — planning, tool use, and multi-step reasoning — grounded in Retrieval-Augmented Generation (RAG) over Amazon Ads knowledge sources.
• Apply reinforcement learning and model fine-tuning (e.g., instruction tuning, RLHF/RLAIF, preference optimization) to adapt large language models to our domain and channels.
• Define and operationalize rigorous LLM evaluation: golden sets, faithfulness/groundedness, precision/recall, and human-in-the-loop evaluation mechanisms that reliably measure and improve quality.
• Own applied engineering quality of the science stack — PyTorch modeling, well-designed APIs, and latency/cost optimization for real-time, production-grade interactions.
• Collaborate with engineering, product management, and business teams to define requirements and ship measurable customer impact.
• Drive continuous improvement through experimentation, iterative development, testing, and optimization.
• Translate complex scientific challenges into clear, impactful solutions for business stakeholders.
• Mentor and guide junior scientists, fostering a collaborative, high-performing team culture, and engage the broader scientific community through presentations, publications, and patents.

Requirements

• 3+ years of building machine learning models for business application experience
• PhD, or Master's degree and 6+ years of applied research experience
• Experience programming in Java, C++, Python or related language
• Experience with neural deep learning methods and machine learning

Preferred

• Experience with modeling tools such as R, scikit-learn, Spark MLLib, MxNet, Tensorflow, numpy, scipy etc.
• Experience with large scale distributed systems such as Hadoop, Spark etc.

Benefits

• 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.