Duolingo is an online language-learning tool that has reached over 50 million language learners since launching two and a half years ago. How are they scaling so quickly? The Duolingo Community.

With hundreds of volunteers, Duolingo was able to empower their community to develop, test, and spread the word about their language courses. In the past year alone, they’ve launched 39 new language courses all with a team of less than 40.

This didn’t just happen overnight. They started small, and the Duolingo community evolved to the point where it could actually develop content alongside the internal team. In this article, we’ll learn how they overcame the challenges of building new language courses from Kristine Michelsen-Correa, Head of Community at Duolingo.

“The Duolingo community is amazing: incredibly supportive, language savvy (of course), and willing to help others learn where they can. They’re all aspirational and kind,” Kristine explains.

In the time she has been there (just over two years), the Duolingo community has grown from 4 million to 50 million language learners all over the world. This is their first time sharing the community story and giving us deep insight into the challenges and triumphs of building a massive community-powered content engine.

First, how does it work? 

When Kristine started in her role at Duolingo, “We thought about ways to grow language courses.” They only had so many people on the internal team to develop courses. This was a long, laborious process that was far from scalable.

“There were bilingual Duolingo community members who wanted to add languages we never thought we’d be able to offer because of the size of our team.” So they had to think outside the office.

They turned to their community members and released what they call the Incubator. The Incubator allows them to scale their entire course-creation engine, bringing in community volunteers and empowering them to teach what they know.


The Incubator works in phases, which we’ll describe in more detail.

Volunteers apply: There is a formal application process for people interested in volunteering in the Incubator.

Phase 1: Courses Not Yet Released

Phase 2: Courses Released in Beta

Phase 3: Courses Graduated from Beta

At this point, they release the course into the world and continue to collect feedback from the community.

The Challenges of Creating User-Generated Content Engines in the Duolingo Community

As they experimented and grew the Incubator, they identified several common challenges that community builders face when developing scalable user-generated content programs and worked to solve each one.

The challenges of creating a user-generated community strategy include:

  1. Accommodating different levels of contribution
  2. Maintaining high quality of content
  3. Making it easy to contribute
  4. Managing multiple languages
  5. Making it engaging to contribute
  6. Determining incentives to participate

1. Accommodating Different Levels of Contribution

In terms of the structure of the volunteer programs, Kristine says they pick the best leaders through the application process and then let them run with it. “We pick the leaders and then contributors pick the people THEY want to volunteer with. We want people to be empowered. We don’t want to make this too regimented.”

Not everyone can contribute in this way, however. It is a high level of involvement. But it’s still important to give people a way to contribute, especially if they’re already clamoring to do it, and to make every contributor feel like their contribution is important. So how do you do this without undermining your own efforts?

While Duolingo empowers their volunteers to create course content, they also find other ways for members to get involved.

“The community also helps with beta testing by going through the course and catching errors as they’re learning,” Kristine explains.

And how did the team even know how best to structure the Incubator and the selection process? They first experimented with forums, which are alive and thriving today in many languages.

We learned a lot about setting up ground rules from the forum program. Always make sure everyone understands why they’re contributing and what the goals are.”

The Incubator is also how we transitioned our in-house language experts into community manager roles, where they were responsible for mentoring volunteers that applied to the incubator.”

2. Maintaining High Quality of Content

“We had to create a way to open up the platform, but also help people through the process.” Quality was a major concern, though Kristine says that the application process helps bring the best possible contributors to the forefront. Even so, they’ve learned there are several concrete ways to ensure that quality remains high:


They leverage their talented in-house language experts to help shepherd the contributors: ”A staff member experienced in language course creation becomes a mentor and is assigned to a language team.” This helps streamline the process and facilitate engagement and quality content.

Constant communication on teams:

“A chat system was created, so that each team developing a course has their own place to communicate with each other.”

Communication among the larger network of volunteers keeps quality high and people motivated.

“There’s also a global and announcements chat where people keep each other informed, a place where tips and even motivational gifs are shared.”

As a result, “There is real community being built between strangers and their link is their passion for languages.” By ensuring that these contributors feel a strong sense of community, they feel more obligated to do a really good job which keeps the quality of the content really high.

3. Making it Easy to Contribute

Duolingo community volunteers collaborate a lot together, and it’s important that the in-house team makes this as easy as possible for them to do. This is why the 3 phase structure to launch a course has been instituted. During each phase, the in-house leaders help volunteers along and keep things moving within the platform.

Phase 1: Content Creation

“This is where the bulk of the content creation comes in. Their community goes in and translates sentences again and again to create the content.” This is all part of the product.

The average time it takes to create a course that is ready for beta is three months. During this time, volunteers spend an average of five hours per week participating in the community, and many spend much more time interacting and contributing.” They have to ensure that the volunteers’ time is well-spent, and so the in-house team takes care of the more technical aspects of course creation.

Phase 2: Content Moderation

During phase 2, courses open to beta learners who provide feedback. The contributors make the changes and keep building a better course.

Phase 3: Launch and Iterate

Feedback is given once the course is totally live. It’s always easy to give feedback and the contributors are given the tools they need to make the changes on Duolingo’s behalf.

duolingo community cmx

In this way, all parts of the process that volunteers help with is within the product itself. They can remain in that one environment and continue to chat with their team while they do so.

4. Managing Multiple Languages

One of the tricky parts of building a global content engine in so many different languages is just that: there are a lot of languages.

Instead of making one big forum for all contributors, they’ve created language-specific chat rooms for volunteer teams so that members can comfortably communicate with each other around the course in one set language. This allows them to create camaraderie around the languages there.

Outside of the Incubator, learners and contributors can also speak in the specific language forums on the Duolingo site, and then to go to the one main Duolingo discussion forum to have conversations around other topics.

Duolingo discussion forum CMX community case study

5. Keeping Contributors Engaged

“We do everything we can to make the volunteer experience one that is rewarding and fun,” says Kristine.

How do they maintain momentum to finish courses?

  1. Cooperation, not competition: One of the key engagement tools they use are the phases of course creation. Everyone works together to achieve the next phase, creating a cooperative model that incentivizes group work rather than individual contribution. When the group levels up, they level up together.
  2. Fun competition among language groups: Members of the community can track their progress and compare themselves to other teams. “This creates healthy competition that drives the different language communities to work to represent themselves in a more positive light.”

Also, the whole team pitches in to help with course creation: “The entire Duolingo team is constantly interacting within our community. Even the engineers are involved in this process and they’re all known by name within the community.

6. Determining Incentives to Participate

With so many different cultures and languages, creating incentives can be tricky. What motivates someone in the US may not motivate someone in Russia or Brazil. However, the team has found that there are several keys to success when determining incentives.

Incentives for Global Communities:

  1. Recommendations: Volunteering time to build a new language course is a huge accomplishment. Offer recommendations for college, graduate school, or jobs. Learn what your community members’ larger goals are and find ways to get them there.
  2. Recognition: When you go to a course page, you’ll see the names of the volunteers that contributed to the creation of that language direction.
  3. Giving back: In Duolingo’s case, people want to teach their language to others. This is a point of pride.
  4. Personal growth: Make sure people are learning along the way. On Duolingo, the process of course creation is an interesting technological challenge. People learn a lot about how language courses are built.

There are many ways to incentivize participation, but the best ones that will spark the deepest engagement are the ones that are intrinsic or scalable: recognition, giving back, and growth.

In Summary, Duolingo’s Advice for a Successful Community UCG Program:

1. Understand that different members will be interested in contributing at different levels of commitment, so build in multiple ways to contribute

2. You can keep the quality of user-generated content high by ensuring there’s a strong leader providing guidance, and creating a sense of community so members feel committed to the group

3. Never ask members to do *too* much. Let them focus on the content and remove as many technological barriers as possible

4. When working with a community comprised of very different groups (ie. language barriers) a good approach is to break those groups out into their own sub-communities so they feel comfortable and connected

5. To keep contributors engaged, create cooperative rewards, or rewards that incentivize the group as a whole rather than just individuals. You can also create competition between groups, creating stronger ties within each group as they’ll feel more like a team

6. When trying to incentivize your community members to contribute, focus on intrinsic incentives as they’ll have the biggest impact

Looking Ahead at Learning Communities of the Future

“We’re improving what’s possible technologically as well as through community,” Kristine explains. This is powerful stuff that is bridging the gap between product and community.

There are always challenges that crop up as you build a community from scratch, but Duolingo keeps approaching them head on as they think about how to build a global community around language learning that will last into the future.

We’re growing up,” Kristine explains. “You need to have a bit more structure as you grow. You’ve got a lot to get done, and you need to make sure everyone is working together. We’re looking towards the future with lots of excitement. We know we can bring access to even more people.”

Carrie Melissa Jones

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