How Duolingo designs product (and why)
A playbook for designing for 500 Million users with high retention.
👋 Hello! Welcome to this week’s ADPList’s Newsletter; 🔒 subscriber-only edition 🔒weekly advice column. Each Tuesday, we tackle design, building products, and accelerating careers. We’re looking for sponsors! If you’re interested in sponsoring our newsletter, let’s chat.
I’m back and thank you for your patience as I recover from our annual, BeMore Festival 2023 and this week, ADPList crossed over 100 Million Minutes of Mentorship Session, which I’m told, makes this community the largest mentorship platform on the internet. Friggin’ mind-blowing.
This week, we’re going to 🔒 share exclusive insight 🔒 on, Duolingo.
This is the most mind-blowing education app.
Duolingo is one of the world’s most successful learning-based businesses. In 2022, it made nearly half a billion dollars in revenue (a 46% increase from the year prior) and had 16.3M daily active users.
But it’s not all good, here’s Duolingo’s big challenge…
It’s easy to be excited about starting a learning journey. But it’s much harder to stick with learning than most people think. A recent study by the MIT found that online courses only have a 4% retention rate. But Duolingo has been remarkably successful keeping people engaged with digital learning. They boast a daily active user retention rate of about 55%.
Why? Because they use psychology and behavioral science to keep us learning.
How Duolingo designs product
Habits are actions performed without conscious thought — like grabbing your morning cup of coffee or going to the gym every day after work.
That’s why turning an app into a habit is the holy grail for every product — and Duolingo has managed to do for millions of users. To understand how…
Enter “Habit Loop,” describes the basic structure behind every habit.
Habit Loops consist of three parts, and all three parts must be present to create a habit.
The trigger (or cue)
The routine
The reward (or feedback)
Playbook 1: Design to create “triggers”
Triggers, also called cues, signal that it’s time to perform a habit. For me, waking up every morning triggers a craving for a cup of coffee — not because I want one but because it’s something I do every morning.
Duolingo uses several triggers to get you to open the app:
1. Emotional Manipulation
Duolingo is famous for its owl character named Duo. He’s got quite a personality (as well as a sometimes NSFW crush on singer Dua Lipa).
He’s an adorable mascot that the brand uses to manipulate its users' emotions and actions. For example — if you don’t use the app for a while you’ll start to get emails with subject lines like:
“You made Duo sad 😢”
“Keep Duo happy”
2. Push notifications
One of the most common ways apps can trigger habits is by using push notifications. Especially those that pull psychological levers like Scarcity, Loss Aversion, or Commitment & Consistency.
