Location
London

Hours
Full Time

Salary
Competitive, commensurate with experience

About the Role
The Alexa International Science team is seeking a passionate, talented, and inventive Senior Applied Scientist with a strong background in speech models (understanding and generation) and deep learning. You will help build industry-leading Generative AI technology focused on speech-to-speech models and multilingual systems. In this role, you will drive cross-team scientific strategy for speech quality across international locales, influence partner teams, and deliver solutions that impact Alexa's global products.

As a Senior Applied Scientist, you will collaborate with peers to develop novel algorithms and modeling techniques advancing multilingual speech generation, text-to-speech synthesis, and speech-to-speech models. Your work will directly enhance natural, expressive, and locale-appropriate voice experiences for Alexa+ customers across multiple languages. Leveraging Amazon's diverse data sources and large-scale computing resources, you will accelerate advances in speech synthesis, voice quality, and pronunciation accuracy for non-English locales.

The ideal candidate has a solid understanding of machine learning, speech synthesis (TTS/S2S), multilingual phonetics, modern model architectures, and evaluation methodologies. You will thrive in a fast-paced environment, tackle complex challenges in low-resource language settings, deliver impactful solutions iteratively based on customer feedback, and align multiple teams around a shared scientific vision for international speech quality.

A day in the life
You will review experiment results and iterate on model architectures for speech generation. Collaborating with software engineers, you will optimize model performance for production deployment and partner with product managers to align research priorities with customer needs. You will participate in science reviews, paper reading groups, and brainstorming sessions with fellow scientists. Your work will directly influence how Alexa sounds and communicates with customers in international markets, providing meaningful solutions at a global scale.

About the team
The Alexa International Tech team supports Alexa's global expansion by building scalable, reliable, and locally relevant AI products. The team develops science, engineering, evaluation, and quality platforms behind global AI product delivery, including multi-model AI orchestration, multilingual model and data readiness, speech and language quality, reward modeling, synthetic data generation, automated evaluation, developer tooling, defect analysis, and launch mechanisms. The team operates at the intersection of applied AI, speech, distributed systems, developer experience, and customer quality automation, enabling teams to build Alexa+ experiences once and scale them across languages, countries, devices, models, and customer expectations without reinventing mechanisms each time.

Experience
- Master's degree or PhD in a relevant field
- Proficient programming skills in Java, C++, Python, or related languages
- Experience with neural deep learning methods and machine learning
- Proven experience building machine learning models for business applications
- Applied research experience

About you
- Strong understanding of machine learning, speech synthesis (TTS/S2S), multilingual phonetics, modern model architectures, and evaluation methodology
- Ability to thrive in a fast-paced environment and tackle complex challenges, especially in low-resource language settings
- Skilled at delivering impactful solutions and iterating based on customer feedback
- Excellent collaboration and communication skills to influence and align multiple teams around a shared scientific vision

Qualifications
- Preferred experience with modeling tools such as R, scikit-learn, Spark MLLib, MxNet, TensorFlow, numpy, scipy
- Preferred experience with large-scale distributed systems such as Hadoop, Spark