Staff AI Research Engineer

Duolingo • Pittsburgh, PA

3d • $220,800 - $331,200

About The Position

Duolingo is seeking an experienced AI Research Engineer to join its Speech team. The team trains custom models to understand the speech of non-native learners and works closely with product teams on features such as Video Call and the learning path. The role calls for experience across machine learning techniques, especially speech modeling—including ASR, TTS, speech-to-speech models, and audio tokenization—and across the ML stack, from feature engineering and training data development to fine-tuning, reinforcement learning, evaluation, deployment, and monitoring.

The engineer will work on a full-stack team alongside frontend, backend, and AI research engineers, contribute to speech and large-scale neural network models, and collaborate across teams to align model outputs with company objectives. As a member of the Speech leadership group, the role also contributes to strategic product and business decisions, mentors team members, and helps deliver high-quality, scalable, and efficient machine learning solutions.

Requirements

• Proven experience as an AI research engineer, for example in speech recognition, TTS, LLMs, or related fields.
• Strong background in training and fine-tuning large models in an applied setting.
• Advanced degree in Computer Science, Engineering, or a related field focused on machine learning or artificial intelligence, or equivalent experience.
• Excellent leadership and communication skills, with the ability to manage and inspire a team.
• Deep understanding of machine learning concepts, frameworks, and best practices.

Responsibilities

• Join a full-stack team of frontend, backend, and AI Research engineers, fostering a collaborative and innovative work environment.
• Contribute to the development and training of speech models and large-scale neural network models.
• Collaborate with cross-functional teams to understand their needs and align model outputs with company objectives.
• Participate in and help drive strategic product and business decision making as a member of the Speech leadership group.
• Stay up-to-date with developments in machine learning, particularly speech models, and apply this knowledge to advance projects.
• Mentor team members and support their professional development.
• Ensure the delivery of high-quality, scalable, and efficient machine learning solutions.

Benefits

• Base salary is supplemented by equity compensation.
• Employee benefits are referenced through a company benefits link, but specific benefits are not listed.

What This Job Offers

• Job Type: Full-time
• Career Level: Senior