Applied Scientist, Alexa AI

About the role

As an Applied Scientist on the Alexa AI team, you will drive the development and deployment of cutting‑edge large language model (LLM) systems that shape how millions of customers interact with Alexa in many languages and locales. You will work at the intersection of research and production, turning the latest AI breakthroughs into reliable, high‑performance customer‑facing features.

Key responsibilities

• Analyze and model customer behavior at scale, creating novel metrics for personal digital assistants across devices, endpoints, and languages.
• Design and implement deep‑learning, policy‑based, and machine‑learning algorithms that directly improve Alexa experiences.
• Adapt large language models through supervised fine‑tuning, reinforcement learning, and preference optimization (SFT, RL, DPO).
• Build and operate automated training, evaluation pipelines, and conduct rigorous online A/B testing.
• Collaborate with engineering, science, and business teams across Amazon to lead high‑visibility programs.
• Take ownership of production systems, including on‑call duties and rapid issue resolution.

Required profile

• PhD or equivalent experience in Machine Learning, Natural Language Processing, or a related field.
• Proven track record of translating research into production‑ready AI solutions.
• Strong analytical mindset with experience in large‑scale data analysis and metric development.
• Excellent communication skills for cross‑functional collaboration.

Required skills

• Machine Learning
• Natural Language Processing
• Large Language Models
• Deep Learning
• Policy‑based Learning
• Supervised Fine‑Tuning
• Reinforcement Learning
• Preference Optimization
• A/B Testing