Case Study: Duolingo achieves faster, more consistent engineering productivity with GitHub

Duolingo empowers its engineers to be force multipliers for expertise with GitHub Copilot

Duolingo wanted to scale its engineering team efficiently while keeping developers focused on improving its language-learning platform. As the company grew from a few repositories to hundreds, it needed a more consistent development process, faster code review, and easier onboarding across teams. Duolingo turned to GitHub Enterprise, GitHub Copilot, and Codespaces to support that challenge.

GitHub implemented custom API-based workflows, standardized code review and testing, and introduced GitHub Copilot and Codespaces to streamline development. The results included a drop in median code review turnaround time from three hours to one, faster repo setup from hours or days to about one minute, and estimated developer speed gains of 25% for new contributors and 10% for familiar ones. With GitHub, Duolingo improved productivity, reduced context switching, and gave engineers more time to focus on product innovation.

Duolingo

Jonathan Burket

Senior Engineering Manager