Severin Hacker

Severin Hacker is the cofounder, CTO, and board director of Duolingo. Born and raised in Switzerland, he moved to Pittsburgh to study for a Ph.D. at Carnegie Mellon University under advisor Luis von Ahn. In August 2011, Hacker and von Ahn cofounded the language learning platform Duolingo. Hacker has served as chief technology officer and a member of the board since the company's founding. By 2021, Duolingo had grown to over 500 million registered users (37 million are active at least once a month), offering ninety-five courses in thirty-eight languages and generating a revenue of $250 million. Hacker also invests in early-stage tech start-ups through hacker.capital and 99 Tartans.

Severin Hacker was born in 1984 and grew up in a small town outside of Zurich, Switzerland, called Zug. His dad is an entrepreneur, and from an early age, Hacker wanted to start a company. He recalls his family being one of the first in his neighborhood to get the internet. Fueled by his interest in video games, he began teaching himself computer programming around the age of twelve:

What originally drew me to computers was video games and the desire to build your own games and understand how those games are built. I was somewhat obsessed.

In 2003, Hacker attended Eidgenossische Technische Hochschule Zurich (ETH Zurich), graduating with a BS in computer science in 2006. During his undergraduate studies, Hacker had a summer internship in 2004 at Actant. In August 2007, he moved to Pittsburgh to study for a Ph.D. at Carnegie Mellon University under advisor Luis von Ahn. In May 2009, he spent five months as a research intern at Microsoft. While studying for his Ph.D., Hacker cofounded Duolingo with Luis von Ahn. In March 2014, he completed his Ph.D. in computer science at Carnegie Mellon University. His research focused on large-scale human computation.

In 2009, two years into his doctoral program, Hacker and his supervisor, von Ahn, were developing ideas to translate web pages into other languages. Von Ahn, who was raised in Guatemala, had previously sold two companies to Google:

• Developed while a Carnegie Mellon Ph.D. grad student, von Ahn worked on a game that crowdsourced information, getting people to label images and improve image search. Called ESP Game, it was acquired by Google in 2005 and renamed Google Image Labeler.
• While a professor, von Ahn developed reCAPTCHA, a start-up with the idea of getting people to help digitize books during website CAPTCHA tests. It was acquired by Google in 2009.

The multilingual pair were dissatisfied with the results when feeding web pages into Google Translate, but they also knew hiring translators was not feasible. Instead, they gamified the problem, developing an app to teach foreign languages for free. When learners reached the highest levels of a course, their translations could be aggregated with other users to produce fully translated web pages. They found compiling the work of multiple higher-level students produced more accurate translations than existing automated solutions. Discussing their solution, von Ahn said:

The solution was to transform language translation into something that millions of people want to do, and that helps with the problem of lack of bilinguals... It is estimated that there are over 1 billion people learning a foreign language. So, the site that we’ve been working on, Duolingo, will be a 100% free language learning site in which people learn by helping to translate the Web. That is, they learn by doing.

In August 2011, Hacker and von Ahne founded Duolingo. Hacker became CTO and a board member. The service launched in 2012. Hacker has discussed the challenge of running the business in the early years while still at university:

The most challenging part was hiring people—this was around 2011 or 2012 when it was Luis and me. We were still at the university back then, but it was so hard to get people to work for Duolingo. At the time, startups weren’t nearly as attractive as today, and people at Carnegie Mellon wanted to go work at Google or Facebook—one of the big tech companies. We heavily relied on friends and referrals in the early days.

In 2013, Duolingo won Apple’s “App of the Year.”

Hacker also invests in early-stage tech start-ups through hacker.capital and 99 Tartans. Companies he has contributed to financially as an angel investor include the following:

• AbiliLife
• Brainbase
• Gridwise
• IAM Robotics
• Intellipse
• ViaHero
• VIT Initiative