Jackson Shuttleworth

Founder-level review of every experiment maintains a high product bar and prevents 'local maxima' traps.

"All of our changes at Duolingo go through product review that are reviewed by Luis, so Luis reviews every single change that we propose, every experiment that we run."

Monetization and retention features often exist in tension, requiring clear prioritization of goals.

"We're actively working on an experiment, right now that's having a small hit to revenue, but it's a really nice win for retention, and I think it's actually worth thinking about from day one, as you'r..."

Habit formation is the core driver of long-term retention in learning products.

"What Duolingo really focuses on is, how do we help users build habits around language learning? Getting user come back the next day is the biggest problem to solve."

Loss aversion becomes a powerful retention lever once a user reaches a seven-day milestone.

"We've looked at the data for our retention curves, and what we found is that once you get to seven days, loss aversion kicks in, and you retain. So, going from a one to a two-day streak, huge jump in..."

Current user retention rate is the most sensitive lever for driving overall DAU growth.

"The metric that is most effective, where a percentage change in that metric is most effective at driving DAUs is current user retention rate (CURR). And this is just users who are not new or resurrect..."

Small, quirky rituals build cohesion and psychological safety in remote teams.

"Whoever's the last person to go would count down 3, 2, 1, and then we'd all try to clap at the same time... Recently we've added, we all say yee-haw in unison afterwards... it sounds so minor, but the..."

High-velocity experimentation is more efficient than prolonged internal debate.

"Duolingo has very much, has a strong test it philosophy, we're willing to test a lot of different... Honestly, we'd much rather test it than debate it for days and days."

Balancing strict mechanics with user flexibility prevents churn when life gets in the way.

"This idea of flexibility versus perfection, and then regardless, celebration, is core to how we think about the streak. Because I think for the streak for us, it's very much a bend not break."

Small changes in micro-copy can significantly alter user intentionality and retention.

"We've actually set up really good infrastructure for copy testing. We used to say continue, our standard CTA is continue, and we changed that to commit to my goal, and it was a massive win."

A North Star metric (DAU) should be supported by a high-sensitivity input metric (CURR).

"Duolingo cares, our growth North Star is DAUs, the metric that is most effective, where a percentage change in that metric is most effective at driving DAUs is current user retention rate."

Metric-based goals provide clearer prioritization than feature-based goals.

"When you can be really laser focused on, my goal each quarter is to make this metric go up, I think it's much easier to make sure that you're working on the highest ROI thing. I think when you think m..."

Shipping the simplest possible version of a hypothesis allows for faster learning and avoids 'whistle' bias.

"We really resist the urge to do the big V1. And I think this is, I shared the streak goal example, where, a lot of times when we're exploring something we will say, okay, well, that's cool, how do we..."

Global user research can reveal cultural disconnects in core product metaphors.

"We did some UXR in India many years ago... the idea of keeping a flame lit to show your commitment to something makes less sense... it was a metaphor for a mechanic, and when we redesigned it... we ac..."

High-velocity experimentation requires rigorous process and automated project management to avoid 'lost cycles.'

"There's heavy Jira automation... making sure that you have really good process around how are you going to run so many experiments... We're planning months out, as we think about these feature iterati..."

The guest discusses deep psychological principles like loss aversion, the 'bend not break' philosophy, and using haptics/animations to create 'pause moments' for celebration that go beyond standard re

"Once you hit seven days, loss aversion kicks in, and you retain."