Duolingo

In April 2025, CEO Luis von Ahn issued a company memo announcing Duolingo would 'gradually stop using contractors to do work that AI can handle.' The policy stated that 'headcount will only be given if a team cannot automate more of their work' and that AI would be used in hiring and performance reviews. Von Ahn stated they would 'rather move with urgency and take occasional small hits on quality than move slowly.' The announcement sparked user backlash including mass app deletions on TikTok.

In January 2024, Duolingo laid off approximately 10% of its contractors - primarily translators and content writers - explicitly citing AI as the replacement. Affected workers reported being told that 'AI can come up with content and translations.' A second round in October 2024 cut another 10% of contractors, this time targeting writers.

In August 2023, data from 2.6 million Duolingo users was released publicly after an API vulnerability allowed scraping of user information. The exposed data included real names, login names, email addresses (not meant to be public), languages learned, XP points, and learning progress. The vulnerability was first exploited in January 2023 when data was offered for sale for $1,500. Despite a researcher publicly disclosing the API flaw in March 2023, the API remained accessible. Duolingo called it 'a scrape' rather than a breach.

In a TED talk titled 'How to Make Learning as Addictive as Social Media,' CEO Luis von Ahn stated: 'What we've done is we've used the same psychological techniques that apps like Instagram, TikTok, or mobile games use to keep people engaged.' Documented dark patterns include streak systems exploiting loss aversion, guilt-based notifications ('Your streak is in danger!'), hearts systems requiring payment after mistakes, and a Brazil campaign using drones to project notifications on buildings near lapsed users' homes.