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.

Math Team

As an iOS engineer on the Math team, you will help build the technology that changes how people around the world learn Math. The features that you ship will help learners to develop core math skills in a fun, engaging way. We’re looking for engineers who love building new products and features.

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.

Core App Performance Team
The Core App Experience team is in charge of improving the user experience in core flows of the iOS and Android apps to drive user growth. Sitting in between the intersection of technical and product work, you will drive technical improvements in app open, session start and end, and improving the offline experience. We're looking for engineers who are willing to deep dive into the codebase and provide their suggestions on how to improve the everyday experience of our users.

🧠 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

We post a multi-level salary range for all of our roles.

This is not inclusive of the rest of our awesome portfolio that includes equity compensation and world-class benefits. Our salary ranges are the same for all US locations. Your recruiter can share more details about the range for a specific level during the hiring process. The actual salary within the range is determined by many factors including but not limited to, skills, experience, education, and internal equity.

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 veteran, status as an individual with a disability, or other applicable legally protected characteristics.

By applying for this position your data will be processed as per the Duolingo Applicant Privacy Notice.

Unfortunately, there is a rise in scammers pretending to be real Duolingo employees. 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 @duolingo.com or @recruiting.duolingo.com. Stay alert and double-check these details before sharing any information.

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