Notebooks have become an essential tool for data science and machine learning research. We felt the existing tools weren't satisfactory for Scala, and lacked the features that developers need in order to productively create reproducible notebooks. So we set out to create a new notebook tool from scratch, which provides essential code editing features that other tools lack, as well as seamless interoperability between multiple languages – including Scala, Python, and SQL – and a host of other improvements that evolve the notebook experience. We'll demonstrate our open-source notebook solution, and talk about why and how we built it – and some of the great Scala ecosystem libraries that allowed us to go from zero to MVP in an unbelievably short time.