How Duolingo Designs with Psychology in Mind

An Interview with Sean Chin, Product Designer

The popular language-learning app Duolingo has a tough mandate: motivate people to do something that’s difficult, time-intensive, and mentally taxing, all while convincing them to come back tomorrow and do it all again.

Sean Chin, a designer at Duolingo, phrases it this way: “At the end of the day, we’re trying to encourage people to do something that’s intrinsically difficult. Learning a language is not easy. That’s why we have to introduce all these mechanics to incentivize learning.”

We spoke to Sean about the role of psychology in design, the origins of Duolingo as a university research project, and the principles and process that drive the app’s design team.

Sean Chin, senior product designer at Duolingo

Tell us about how you got started at Duolingo.

I landed at Duolingo kind of like a romantic comedy. The story started long before I got here. I don’t know if you know, but Duolingo was first a research project out of Carnegie Mellon University in Pittsburgh, and it spun out to become its own startup in 2011. In that time, I was an undergrad at Carnegie Mellon, and the Duolingo project was first announced at a TEDx event by our CEO. I was in the audience for that — I was in the room when it was announced, and that officially was when it got onto my radar. And then, senior year of college, one of my class projects was taking psychology principles and applying them to a real business, and my case study was Duolingo. That was my “client” for the semester. I visited the office and got to talk to some of the designers, but I actually did not join Duolingo until a year and a half after graduation. Immediately after school I worked at a design agency for some time, and then moved into Duolingo two-and-a-half years ago.

How does design fit within Duolingo’s culture?

It’s kind of a cliché at this point, but design is definitely a widely valued part of our business. It certainly helps that our CEO and most of the leadership really do value design, and I think that was made clear from the start. Designers are embedded in pretty much every team we have — equal seat at the table. All of our product decisions are made with a designer’s perspective. Often the actual mockup or sketch being the vehicle for a lot of these conversations. I think ever since the early success of the product, everyone quickly realized that our success in the marketplace was because of our unique and — at that time — very novel user experience. So, I would say it’s never been a point of conflict. Design is incredibly important to everyone here.

How many designers does Duolingo have?

Today we have eight designers. Of that eight, six are product designers, meaning they’re touching the UI, helping design new features for our various apps. And we have two branding designers. They help out with a lot of our marketing initiatives, anything print related, or if we need a new illustration even for our products they’ll help out.

How does your design team collaborate?

Collaboration happens in many ways, and it’s certainly an evolving thing as we’re growing. I would say that most effective collaboration happens at the desk with a few of us, but now as we’re growing we find that it’s a little harder to get that spontaneous, walking up behind someone’s shoulder and taking a look at what someone else is working on, approach.

We have our suite of tools. We’re chatting all day, we have Slack, we have email. Wake certainly has become one of our new favorite tools. We do something here… it was originally an engineering practice called “pair programming.” The idea was, you’d pair up two random engineers, and one of the engineers would work through a problem and the other would shadow. The design team adopted that, so every month we’d get paired up with one other designer and just shadow them for an hour. Maybe pick up a new shortcut, or just get a little bit of exposure to what they’re working on that month. But I would say primarily it’s pretty informal. We each have a design manager — not really an art director, but someone who’s been around longer — to bounce ideas off of. We’ll have one-on-ones every two weeks or so. We’re slowly starting to introduce more formalized processes to help facilitate that kind of collaboration.

How has Wake changed the way that you work?

For a long while, our design team was just four people, and with four people it’s pretty easy to know what everyone else is working on. Especially with a smaller team, a smaller office, you can just walk up or look over to see what someone else is working on. But now that we’re eight designers, I think Wake has been a godsend.

We treat Wake in a very casual way. Any time we post to Wake, we’re not necessarily saying that it’s a final draft — it’s more like, at this moment in time, here’s a snapshot of what I’m working on. And since we treat it in a casual way, it lets us get a quick eye into what other designers are working on. So even though you guys are working on very different products, we can at least make sure we’re using the same brand, same colors, we’re not deviating too much from our guidelines. That kind of thing. We integrated it into our Slack room, so any time someone posts to Wake we all get a notification.

I think we might use Wake in a different way than other teams. We don’t use it as a vehicle for formal feedback, as much as a way to encourage people to continuously post. It reduces friction. Many designers have the same anxiety: any time I post something, it’s open to criticism. Instead, we want it to be a free zone to just put stuff up without any fear. In that regard, we also just keep it designers-only, so it’s not opened up for the whole company to see, because we know the whole company would get excited about seeing some wild experiments that might not actually work out. We like to keep it our sandbox: a judgment-free zone where anyone can post anything.

What non-design class or resource has been most influential in your career?

In college, I didn’t study design formally — that seems to be a growing trend with designers these days. I took a lot of decision science and psychology classes, mostly because that kind of stuff really interested me, so learning more about general behavior patterns and tendencies people have in given situations… I think that helps inform the digital product decisions we make. At the end of the day, we’re trying to encourage people to do something that’s intrinsically difficult. Learning a language is not easy. That’s why we have to introduce all these mechanics to almost incentivize learning. Just like going on a diet or losing weight or sticking to a workout plan, learning a language takes a lot of diligence and commitment. Often times, I’ll find myself referring back to some principles I learned in a Psych 101 class or Cognitive Psychology class that seems really applicable to the problem at hand.

What does your team do differently than other design teams?

For the most part — and this is only in talking to other designers at other places — we don’t really have a structured process for stuff. In general, we start our design cycle at a high fidelity, so we will do the occasional sketch just to rough out an idea, but so much of our design guidelines and patterns have been designed already that it’s often easier and quicker for us to jump into a design process at high-fidelity, skipping wireframes and all that kind of stuff.

Also very different, there’s a big testing culture at Duolingo. From the start, all the engineers and all the product teams have embraced an A/B testing religion of sorts. Everything we do is by the scientific method. We’re not going to introduce a new feature without validating that it works. So I think, to that end, there’s this culture where we reduce as much friction and time-wasting to getting something out the door. If we start the design process at a high fidelity, get it into implementation, get metrics and feedback quickly, then we can know what to do next.

In that regard, our design team starts our process at a high fidelity. I think there’s less attachment to each feature because we know that things can evolve very quickly. But I think we’re very systematic in the way that we introduce things. We’d rather introduce a modular design feature rather than a complete overhaul, because we know that we can validate certain aspects or introduce a new feature separately and see if it works rather than commit a lot of time into a complete redesign of something, only to revert it later.

I think our designers are very scientific in their approach. All of us pay attention to the metrics. I know at other companies they have a separate data science team, or only the engineers are paying attention to the metrics. All of our designers are encouraged to get intimate with Mixpanel and all the internal tools to make sure we have a direct understanding of the implications of our design. We’re very data-driven in that way.

Duolingo’s office in the East Liberty neighborhood of Pittsburgh, PA

What do you think is the biggest challenge facing the design world today?

Today’s designer is no longer a specialist inserted at the end of the product development cycle — design is ubiquitous. Every business needs to value design and recognize its importance to succeed. Designers aren’t just creating a series of icons or mocking up static screens, designers are creating ecosystems. The designer is now challenged to craft an entire experience that could transcend the screen into the real world. The product is no longer just a set of pixels. It’s really this culmination of everything — the language in the copy, the marketing materials, the sounds, the animations, the flows.
Users are now expecting well executed experiences, so there is pressure to get this right. When every new app is introducing some novel interaction or flashy animation, we need to ask ourselves “Would this actually help our users?” before giving into the latest design trend. There needs to be diligence in the details — nothing should be arbitrary. If we are doing our job correctly, the design of our product should help our users accomplish their goals, rather than be the focus of their attention.


Thanks to Sean Chin for sharing his insights about design and collaboration. You can follow him on Twitter, and see what he and the Duolingo team have been building at duolingo.com.


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