Senior​/iOS Engineer II

About the role

We are hiring for multiple levels for any one of the following teams. Leveling is usually determined once all interviews are completed.

The Delight team makes Duolingo feel more fun, rewarding, and motivating by adding delightful moments throughout Duolingo's core app experiences like lessons. The team experiments with experiences such as lesson combos, random reward chests, lesson completion animations, sound effects, and haptics.

Duolingo's Monetization pillar builds the systems that fund our mission. As a Senior iOS Engineer on the Ads team, you will work on a product engineering team responsible for growing and scaling Duolingo’s ads business by delivering high‑quality ads that delight learners and fit seamlessly into our product experience while contributing to the company’s bottom line. The team owns the systems behind ad serving, mediation, demand, in‑product ad formats and surfaces, and more.

You will collaborate 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 native iOS applications, primarily in Swift
• Mentor and set technical direction for junior engineers across the company

• A Bachelor’s degree in Computer Science or a related technical field
• A solid foundation in computer science with strong competencies in data structures, algorithms, and software design
• Programming experience in Swift

• Strong proficiency in Swift, with proven ability to build and maintain production‑level applications
• Strong technical knowledge of iOS mobile application development for iPhone and iPad using Swift with Cocoa Touch and related frameworks
• Experience designing clean and maintainable APIs
• Experience with multithreaded programming
• Experience writing unit tests and testable code
• Knowledge of iOS SDK performance tools and optimization techniques

We care for our employees' holistic well‑being through a comprehensive benefits program.

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.

The offered salary is dependent upon several factors, including work experience, skills, and internal peer comparisons. The posted range is USD 177,700 — 240,400. Base salary is supplemented by equity compensation.