This is the mind map I made based on the contents of the second chapter of The Duolingo Handbook .

The second chapter “Raise the bar” is about how at Duolingo they strive for excellence as a baseline. This chapter explores this ambition by starting to talk about how important it is to take ownership, which is fundamental to ensure accountability and excellence. From the concept of ownership, it moves on to the cultural aspect of feedback, where direct feedback is promoted following the concept of “hard on the work, easy on the people”.

Concerning product development, there is a brief explanation of the four main guidelines for developing new features: useful, intuitive, delightful and polished.

Finally, they explain an interesting theory that at Duolingo they prefer to release a polished product that meets minimum quality standards, rather than MVPs that lower the quality bar.