Duolingo · Execution · Entry · 45 to 60 minutes

Improve streak based retention at Duolingo

Duolingo is a language learning app that uses short lessons and habit building features to help people study every day. Answer this product management case and get it graded line by line against a weighted rubric.

problem framing
hypothesis design
experimentation
metrics
tradeoff judgment

The situation

You are a PM on Duolingo's Growth Team. Many learners set a daily goal and build a streak by meeting it every day, and the streak is already visible across the app. Reminder messages can also reference a learner's streak. Internal research and forum feedback suggest that streaks matter a lot to users, people feel proud when they keep them and frustrated when they lose them after a single missed day. At the same time, usage tends to peak in the middle of the week and fall on weekends. Your manager wants one small experiment in the next release that could improve retention by helping learners maintain a healthy language learning habit. You need to recommend where to focus and how to test it. The team is debating whether streaks should feel more motivating, less fragile, or both, but you only get one lightweight test this cycle. The tension is that a feature that increases short term activity could also create burnout, cheapen the meaning of the streak, or mostly help highly committed users instead of the broader learner base.

What to produce

A one page product brief, 500 to 700 words.

Your answer must

Define the target user segment and the specific behavior problem you want to change.
Propose one lightweight streak related feature experiment and explain the hypothesis behind it.
Describe the user flow and where the feature appears in the current Duolingo experience.
Specify one primary success metric, two guardrail metrics, and a clear success threshold.
Outline the A/B test design, including eligibility, control versus treatment, and how you would decide what to do next.

Constraints

Do not change the core rule that a streak is earned by meeting the daily goal each day.
Keep the scope to one lightweight experiment that can use existing surfaces such as lesson completion, the home screen, reminders, or the in app store.
Do not redesign lesson content or depend on cash rewards, new partnerships, or offline programs.

Format

Use five labeled sections: user problem, hypothesis, feature flow, experiment and metrics, risks and next step.

How Duolingo actually played it

Two streak experiments from Duolingo's growth team: a wager that locks in a seven day streak, and a weekend protector. The post gives the hypotheses and the retention lifts.

Turn a habit insight into a small testable feature
Report the lift on a specific retention day
Protect users from weekend streak loss

Built from How Streaks keep Duolingo learners committed to their language goals by Kai Herng Loh.