Backend Software Engineer (Senior/Staff/Senior Staff)

Our mission at Duolingo is to develop the best education in the world and make it universally available. But we’ve got more left to do — and that’s where you come in! Duolingo is the world's most popular learning app. Beyond our core learning product, we also offer English proficiency testing with the Duolingo English Test, and are bringing new subjects into the Duolingo app, where people can develop their Math and Music skills. We are passionate about educating our users, making fact-based decisions, and finding innovative solutions to complex problems. We offer meaningful work, limitless learning opportunities, and collaboration with world-class minds. Come brighten your life and over half a billion more! As a Backend Engineer you will work on building the APIs that power our products and give our learners a best-in-class experience. Our microservices infrastructure is composed of hundreds of endpoints serving hundreds of millions of requests per day. You will partner with your team members on identifying requirements and designing services that are fast, resilient, and cost effective. You will have ownership over the entire lifecycle of your services and associated infrastructure, and ensure they are always operating well. Read about the technical problems our Engineers work on  Below you can find more information about teams we're hiring for Architecture Team:  The Architecture team’s mission is to ensure that Duolingo’s software continues to scale as we grow. We work on some of the largest and most critical infrastructure run by Duolingo and provide tools and best practice guidance to teams as they look to create new features and services.  In this role, you will lay the groundwork for the future success of Duolingo’s software platforms. Music Team: As a Backend engineer on the Music team, you will help build the technology that changes how people around the world learn Music. The features that you ship will help learners to develop core music skills like sight reading and ear training in a fun, engaging way. DET Test Scoring Team: As an engineer on the Scoring team for the Duolingo English Test, you will help advance the state of the art in language testing. You will work closely with AI researchers and assessment scientists to pioneer innovative and AI-driven ways to assess language ability, while maintaining critical infrastructure and strengthening the test’s reliability. You will advance the team’s mission to lower barriers and increase opportunities for English language learners everywhere. DET Proctoring Operations Team: The Proctoring Operations team’s mission is to ensure that we provide high-quality and efficient human proctoring for all Duolingo English Test tests. In this role, you will take on full-stack web development work. You will primarily work on the ‘proctor portal’ an in-house tool used by contractors for proctoring the test. You will also work closely with the anti-cheating team to take new signals developed by them and put them in the hands of proctors. Data Infrastructure Team: As a Backend engineer on the Data Infrastructure team, you will build and maintain critical infrastructure for ingestion, storage, and visualization of all of Duolingo's data (that's billions of items of data each day!). Learning Scaling Area: The Learning Scaling Area’s mission is to ensure that all of Duolingo’s learners have access to high-quality educational content. We leverage pedagogical experts and AI to create content for over 100 courses. You will be responsible for building and improving the infrastructure and tooling that drives content creation. Learning R&D Area: The Learning R&D Area works on improving the learning experience of our users with new bets, technologies, and features, that fill the learning gaps in our product. Our goal is to make Duolingo the best way to level up your language skills, regardless of your proficiency level. Responsibilities 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 Requirements A Bachelor’s degree in Computer Science or 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 providers We will do everything we can within reason to make sure that your interview takes place in an environment that fairly and accurately assesses your skills. If you need assistance or accommodation, please contact your recruiter. Take a peek at how we care for our employees' holistic well-being with our benefits here. Duolingo is proud to be an Equal Employment Opportunity employer. We do not discriminate based upon race, religion, color, national origin, gender (including pregnancy, childbirth, or related medical conditions), sexual orientation, gender identity, gender expression, age, status as a protected veteran, status as an individual with a disability, or other applicable legally protected characteristics. By applying for this position your data will be processed as per the Duolingo Applicant Privacy Notice. We post a multi-level salary range for all of our roles. This is not inclusive of the rest of our awesome portfolio that includes equity compensation and world-class benefits. Our salary ranges are the same for all US locations. Your recruiter can share more details about the range for a specific level during the hiring process. The actual salary within the range is determined by many factors including but not limited to, skills, experience, education, and internal equity.