Senior Software Engineer, Backend

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. Below you can find more information about the team we're hiring for: Duolingo Score Team: Duolingo Score is how we reflect a learner's real language proficiency back to them. As the 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. 🧠 You will... Collaborate on software projects with product design and backend aspects Develop, release, and maintain backend services and/or infrastructure Lead individual project priorities, milestones, and ensure we're always shipping ✅ You have... A Bachelor’s degree in Computer Science or a related technical field Strong competencies in data structures, algorithms, and software design Experience programming in Java, Python, or Kotlin Solid understanding of one or more database technologies ⭐ Exceptional candidates will have... Industry experience building high-traffic APIs using public cloud prov