Software Engineer I

About the role

You will collaborate with product managers and designers to drive user growth and deliver high-quality learning experiences to millions of learners worldwide. In this role, you will develop, release, and maintain native iOS applications, primarily using Swift, while contributing to code reviews and working cross-functionally to ensure quality and scalability. You will gain hands-on experience running experiments on iOS and playing a key part in improving critical metrics such as daily active users (DAU). Your work will directly support Duolingo's mission of making the best education in the world universally available. You will own meaningful features that shape how half a billion learners around the world engage with language learning every day.

Key facts

What you'll do

• Collaborate with product managers and designers to drive user growth and define experiments that expand our reach.
• Develop, release, and maintain native iOS applications, focusing on clean architecture and robust implementation in Swift.
• Contribute to code reviews and pair with teammates to uphold coding standards, share knowledge, and ensure scalability.
• Work cross-functionally with design, product, and data teams to translate requirements into high-quality mobile experiences.
• Run experiments on iOS, analyze results, and iterate based on data to improve key engagement metrics.
• Take ownership of the development lifecycle, including task estimation, implementation, testing, and deployment to the App Store.
• Partner with backend engineers to integrate APIs and services that power our learning features and user workflows.
• Monitor app performance and stability, using diagnostics and logging to identify and resolve issues quickly.
• Advocate for best practices in mobile development, security, and accessibility across the team.
• Support the continuous improvement of our build pipelines and development tooling to increase efficiency.
• Write unit and UI tests to ensure reliability and prevent regressions as features evolve.
• Communicate progress clearly in standups and documentation, keeping stakeholders aligned on priorities and risks.
• Learn from senior engineers and share insights with peers to lift the overall technical capability of the team.
• Explore new iOS technologies and propose improvements that enhance user experience and app performance.
• Maintain a strong focus on deadlines and deliver high-quality work in a fast-paced, agile environment.

Requirements

• Graduated or will graduate with a B.S. or M.S. degree in Computer Science or a related technical field (such as math, physics, or data science) before summer 2026.
• 0-1 years of professional experience programming in one or more of the following languages: Java, Python, Swift.
• Demonstrated dedication to Duolingo's mission of universally available education and a passion for learning.
• Willingness to relocate to Beijing, China, as this position is based in Beijing.
• Strong problem-solving skills and the ability to write clean, maintainable code.
• Excellent understanding of fundamental computer science concepts, including algorithms, data structures, and complexity analysis.
• Familiarity with version control systems, particularly Git, and experience working in collaborative development environments.
• Clear communication skills in English, both spoken and written, to effectively collaborate with global teams.
• Eagerness to learn quickly, take ownership of tasks, and contribute independently with minimal supervision.

Nice to have

• A GPA of 3.6 or higher, demonstrating academic excellence.
• Experience contributing to open source projects or personal apps published on app stores.
• Prior exposure to agile development processes such as Scrum or Kanban.
• Knowledge of networking concepts and experience with RESTful APIs.
• Understanding of mobile performance optimization, memory management, and battery efficiency best practices.
• Familiarity with automated testing frameworks and continuous integration tools.

Practical notes

• This role requires relocation to Beijing, China, and is based there.
• The position is full-time and follows standard working hours as defined by local regulations.
• Visa sponsorship and related support will be provided for eligible candidates.
• Applicants are encouraged to apply promptly, as early review of applications is recommended.