More than 170K children go online for the first time every day and more than 40% of new internet users are kids. But as developers are we aware of how children are using our products? And do we know how to specifically engage with them if they are? Kids are rapidly becoming an online audience that engineers canâ€™t (and shouldnâ€™t) ignore. In this talk we explore the technical and ethical challenges developers face when building privacy-first and zero-data products and services to interact safely with the ever growing population of children online.