In this talk, Cristiano Betta, a developer experience expert at his own company, shows us the seven deadly sins of developer onboarding. Taking us step by step through each one, showcasing how even big companies like Twilio and Stripe occasionally get it wrong. Along the way he highlights the common misconceptions and anti-patterns most developers and user experience designers fall for. By the end, you will have had some laughs, some cries, and hopefully learned that user-centered design can be applied to every user, even developers.