As we branch out into subjects like math and music, the biggest challenge is creating a learning experience that is as engaging and effective as our language courses.

We initially underestimated the complexity of teaching languages, but through A/B testing and hiring experts in second language acquisition, we significantly improved our teaching methods.

We realized that instead of creating standalone apps for new subjects like math, we should integrate them into the main Duolingo app to enhance user experience.

We initially thought we were targeting science specialists, but we found that elementary teachers, who often feel unprepared to teach science, were actually the ones who needed our help.

Our strategy involves expanding our English learning product to include various formats, such as one-on-one and one-to-four teaching models, catering to a wider age range of students from young children to teenagers.

We always knew we could grow users first, which was our primary focus in the early days of Duolingo.

We should strive to provide every person with a personalized tutor in their own language to enhance learning from an early age.

Initially, we attempted to create a co-pilot for mechanical engineering, but we pivoted to focus on coding because we were more passionate about it and recognized the potential for AI to transform programming.

From the beginning, Duolingo's goal was to teach languages using AI instead of human teachers, as humans are expensive and not scalable.