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Salary: USD 177,700 - 240,400 / annual
Duolingo is hiring Senior iOS Engineers to join one of two teams: the Delight Team or the Ads Team. The Delight Team focuses on making Duolingo feel more fun, rewarding, and motivating by adding delightful moments throughout the core app experience—including lesson combos, random reward chests, animations, sound effects, and haptics. The Ads Team works on Duolingo's monetization pillar, building systems that fund the company's mission. As a Senior iOS Engineer on Ads, you'll own product engineering for growing and scaling Duolingo's ads business, including ad serving, mediation, demand systems, in-product ad formats, and surfaces. You'll work cross-functionally with product, design, data science, machine learning, and ad operations teams.
In this role, you will collaborate on software projects with product design and backend teams, develop and maintain native iOS applications primarily in Swift, and mentor junior engineers while setting technical direction across the company. You'll work on a massive scale—Duolingo has over 500 million learners globally and runs 300+ experiments simultaneously to drive data-informed decisions.
Required qualifications include a Bachelor's degree in Computer Science or related technical field, strong fundamentals in data structures, algorithms, and software design, and programming experience in Swift. Exceptional candidates will demonstrate strong Swift proficiency with production-level applications, deep iOS mobile development knowledge for iPhone/iPad using Cocoa Touch frameworks, experience designing clean APIs, multithreaded programming expertise, unit testing and testable code practices, and knowledge of iOS SDK performance tools and optimization techniques.
Duolingo's engineering culture emphasizes finding innovative solutions to complex technical problems, running extensive experiments with a massive user base, and providing limitless learning opportunities and mentorship from world-class engineers. The role offers the chance to work on meaningful, fun projects with large scope while contributing to Duolingo's mission to develop the best education in the world and make it universally available.
