About this role
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.
We’re looking for backend engineers who have experience building and operating reliable, scalable systems. Your background may be in product engineering, infrastructure, platform engineering, or a combination of these. What matters most is strong backend fundamentals, sound systems thinking, and the ability to take ownership of complex technical problems from design through production.
Below you can find more information about the team we're hiring for:
Duolingo Score:
Duolingo Score is how we reflect a learner's real language proficiency back to them. As the team lead / backend engineer on this small, high-impact team, you'll help make learners care about their score as much as they care about their streak. You'll partner closely with the Score Pillar's product and design team and our iOS and Android engineers, working on the systems that power score calculation, proficiency modeling, and how score surfaces across the app — including integrations with external platforms like LinkedIn, so learners can showcase their proficiency beyond Duolingo.
Time Spent Learning:
The Time Spent Learning team is dedicated to motivating learners to spend more time engaging meaningfully with the Duolingo app. Our mission is to grow genuine, sustained learning time by designing and iterating on the mechanics that motivate consistent, high-effort practice so learners make real progress toward fluency each day. As a small, cross-functional team of product, design, and engineering, we own a metric that shapes learning outcomes for millions of users and get to shape the Duolingo experience.
Ads:
Duolingo's Monetization pillar builds the systems that fund our mission — from subscription packaging and advertising to ML-powered personalization. As a Backend Engineer on the Ads team, you'll work on a product engineering team responsible for growing and scaling Duolingo's ads business: high-quality ads that delight learners, fit seamlessly into the product experience, and meaningfully contribute to our bottom line. The team owns ad serving, mediation and demand, in-product ad formats and surfaces, and more. You'll work cross-functionally with product, design, data science, machine learning, and ad operations.
Observability:
The Observabili