Senior AI Research Engineer - LLMs, Speech & Equity

TrulyHired; New York (NY); On-site; USD 197,000 - 267,000; Full time

Job summary

Duolingo is seeking a Senior AI Research Engineer to join our Video Call team. You will lead the development and training of ML models, including large language models, speech recognition, and text-to-speech systems, shaping products used by hundreds of millions of learners worldwide.

The role spans the full ML stack—from feature design and data creation to fine-tuning, deployment, and monitoring. You will mentor teammates, collaborate with frontend and backend engineers, and help steer product

Qualifications

• Proven experience as an AI research engineer, e.g., in LLMs, multimodal modeling, speech, or related fields.
• Strong background in training and fine-tuning large models in an applied setting.
• Advanced degree in CS/Engineering/ML or equivalent experience.
• Excellent leadership and communication skills, with the ability to lead and inspire a team.
• Technical depth to guide architecture and implementation tradeoffs, evolve quality standards, and mentor engineers.
• Deep understanding of ML concepts, frameworks, and best practices.

Responsibilities

• Join a full-stack team of frontend, backend and AI Researchers to foster collaboration.
• Develop and train ML models, including LLMs, speech and text-to-speech systems.
• Collaborate with cross-functional teams to align model outputs with company goals.
• Influence strategic product and business decisions with Language Learning leadership.
• Stay up-to-date with ML advances and apply them to our projects.
• Mentor team members and support their professional growth.
• Ensure high-quality, scalable ML solutions.

Skills

LLMs

Multimodal modeling

Speech models

Training large models

Leadership

Communication

Education

Advanced degree in Computer Science, Engineering, or related field with focus on ML/AI

Tools

ML frameworks

Job description

Duolingo is seeking a Senior AI Research Engineer to join our Video Call team. You will lead the development and training of ML models, including large language models, speech recognition, and text-to-speech systems, shaping products used by hundreds of millions of learners worldwide.

The role spans the full ML stack—from feature design and data creation to fine-tuning, deployment, and monitoring. You will mentor teammates, collaborate with frontend and backend engineers, and help steer product