A culture like Duolingo’s doesn’t come from some corporate playbook - it had to be built from scratch. We started with a few dozen nerds above a Pittsburgh sports bar, fueled by a wild dream to make the world’s best education accessible to everyone. Today, we're a ~$16B* company with 800+ employees, but we've held on to what makes us special: a truly quirky culture, endless experiments, an obsession with thinking long-term, and our slightly unhinged sense of humor. After 14 years of figuring out what works (and what doesn't), we decided to write it all down. The Duolingo Handbook captures our core principles through stories of wins, failures, and plenty of surprises along the way. It's not a blueprint – it's a look inside a culture that's helped us build something unique in tech.