Senior/iOS Engineer II

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. 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. Notifications Team As an iOS engineer on the Notifications team, you will build features that empower learners to build long-term habits by improving how we schedule, personalize, and deliver notifications. You will design and implement meaningful notification experiences while collaborating with backend, data science, and product teams. Notifications are fundamental to Duolingo, and we’re looking for engineers who are energized about experimenting and shipping features end-to-end. Ads Team: Duolingo's Monetization pillar builds the systems that fund our mission: from subscription packaging and advertising to ML-powered personalization and beyond. As a Senior iOS Engineer on Ads, you'll work on a product engineering team responsible for growing and scaling Duolingo's ads business: bringing high-quality ads that delight learners, fit seamlessly into our product experience, and meaningfully contribute to Duolingo’s bottom line. The team will own the systems behind 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. 🧠 You will... 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 ✅ You have... 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 ⭐ Exceptional candidates will have... Strong proficiency in Swift, with proven ability to build and maintain production-level applications Strong technical knowledge of iOS mobile application development for iPhone/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 The offered salary is dependent upon several factors, including work experience, skills, and internal peer comparisons. The posted range is subject to change in the future. For this role, base salary is supplemented by equity compensation. We encourage you to talk with your recruiter for more information related to compensation for this role! Salary Range: $177,700 — $240,400 USD Take a peek at how we care for our employees' holistic well-being with our benefits here . 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 accommodations@duolingo.com . 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 ve...