Staff AI Research Engineer

Our mission at Duolingo is to develop the best education in the world and make it universally available. It’s a big mission, and that’s where you come in!

At Duolingo, you’ll join a team that cares about finding innovative solutions to complex technical problems, running countless experiments (300+ at a time!) with our massive user base to make data-driven decisions, and educating our users and employees alike. You’ll have limitless learning opportunities, mentorship and collaboration with world-class minds, and a variety of projects with large scopes — while doing work that’s both fun and meaningful.

Join our life-changing mission to develop education for our half a billion (and growing!) learners around the world.

About the role...

We are looking for an experienced AI Research Engineer to join our Duolingo Monetization team. The ideal candidate will have a proven track record as an AI research engineer, with extensive experience across various machine learning techniques including large language models, multi-armed bandits, and more. They will have experience at all levels of the ML stack, including feature engineering, developing training data, fine-tuning, reinforcement learning, quality evaluations, deployment, and monitoring. On the Monetization team, we’re building AI systems to improve the learning experience while driving our business, including deploying our research into bandit models to balance revenue and retention. Given the broad set of AI domains, broad experience in AI/ML is highly desirable.

🧠 You will...

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

✅ You have...

• Proven experience as an AI research engineer, for example, in LLMs