Applied Scientist II, Alexa International Tech

Alexa International is looking for a passionate, talented, and inventive Applied Scientist to help build industry-leading technology with Large Language Models (LLMs), ASR, TTS, and Speech to Speech models, requiring strong deep learning and generative models knowledge. You will contribute to developing novel solutions and deliver high-quality results that impact Alexa's international products and services.

Key job responsibilities

As an Applied Scientist with the Alexa International team, you will work with talented peers to develop novel algorithms and modeling techniques to advance the state of the art with Large Language Models (LLMs), ASR, TTS, and Speech to Speech model. Your work will directly impact our international customers in the form of products and services that make use of digital assistant technology. You will leverage Amazon's heterogeneous data sources, unique and diverse international customer nuances and large-scale computing resources to accelerate advances in text, voice, and vision domains in a multimodal setup.

The ideal candidate possesses a solid understanding of machine learning, natural language understanding, modern LLM architectures, LLM evaluation & tooling, and a passion for pushing boundaries in this vast and quickly evolving field. They thrive in fast-paced environments to tackle complex challenges, excel at swiftly delivering impactful solutions while iterating based on user feedback, and collaborate effectively with cross-functional teams.

• Analyze, understand, and model customer behavior and the customer experience based on large-scale data.
• Build novel online & offline evaluation metrics and methodologies for multimodal personal digital assistants.
• Drive research in ASR, TTS, and Speech-to-Speech (S2S) model training and fine-tuning
• Advance multilingual speech recognition and synthesis using LLM-based architectures
• Fine-tune/post-train LLMs using techniques like SFT, DPO, RLHF, and RLAIF.
• Collaborate with partner teams on evaluation frameworks and post-training methodologies.
• Communicate solutions clearly to partners and stakeholders.
• Contribute to the scientific community through publications and community engagement.
• 3+ years of building machine learning models for business application experience
• PhD, or Master's degree and 4+ years of CS, CE, ML or related field experience
• Experience in patents or publications at top-tier peer-reviewed conferences or journals
• Experience in any of the following areas: algorithms and data structures, parsing, numerical optimization, data mining, parallel and distributed computing, high-performance computing
• Experience programming in Java, C++, Python or related language
• Deep expertise in ASR/TTS architectures, end-to-end speech models, and LLM integration with speech systems
• Experience using Unix/Linux
• Experience building machine learning models or developing algorithms for business application
• Deep expertise in state-of-the-art LLM architectures, training, evaluation, and post-training techniques (SFT, DPO, RLHF, RLAIF)

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