Senior/Software Engineer II, Backend

About the 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.

Responsibilities

• As a Backend Engineer on the Ads team, 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.
• As a member of the AI Tooling and Ecosystem Team, develop and maintain tools and services that power Duolingo's use of AI in the product. Design systems for managing datasets, evaluating the performance of AI models, and building AI workflows. Help shape how Duolingo builds features using AI, enabling teams to easily define quality metrics, combine human and AI feedback, and compare model performance across different use cases.
• 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 a related technical field.
• Strong competencies in data structures, algorithms, and software design.
• Solid understanding of one or more database technologies.

Skills

• Experience programming in Java, Python, or Kotlin.

Qualifications

• Industry experience building high‑traffic APIs using public cloud providers.
• Experience with industry observability technology, such as OpenTelemetry, Grafana, Prometheus, or DataDog.

Pay

The offered salary is dependent upon several factors, including work experience, skills, and internal peer comparisons. The posted range is $182,800—$247,300 USD, and base salary is supplemented by equity compensation. Please talk with your recruiter for more information related to compensation for this role.