Software Engineer II, Backend

Our mission at Duolingo is to develop the best education in the world and make it universally available. At Duolingo, you’ll join a team that cares about finding innovative solutions to complex technical problems, running countless experiments with our massive user base to make data‑driven decisions, and educating our users and employees alike.

As a backend engineer on the Content Infrastructure Team, you’ll build features that make up the core backbone of the learning experience on Duolingo. Our short‑form lessons are where learners spend the majority of their time on the app, and our team's mission is to build and update infrastructure to enable quick iteration and improve content quality in these sessions. You’ll work on scaling new exercise types that support learners in practicing speaking or grammar in bite‑sized formats and re‑architecting our infrastructure to set our teams up for success in the future.

• Design and implement scalable systems that improve the quality of short‑form sessions.

As a Senior iOS 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.

• 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 are always shipping.

• 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.

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

Salary Range: $153,000 – $207,000 USD. Equally, base salary is supplemented by equity compensation. Benefits include a comprehensive benefits package that supports holistic well‑being.

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

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.

We want to make it clear that Duolingo and our employees will never ask for your Social Security number, bank details, or passport info, and we’ll never ask you to deposit a check, purchase equipment, or exchange money during the interview process. Real Duolingo employees always use an email that ends in  or  Stay alert and double‑check these details before sharing any information.