Typescript was built by Microsoft for this very purpose - helping developers manage large and complex Javascript codebases. But simply using Typescript will not magically make your code scalable. In this talk, I'll explain some key architecture and implementation principles that can leverage Typescript abilities and allow your Javascript code to scale. We will start by understanding what are the prerequisites for a scalable project and will see how to achieve them one by one and how to know if we have succeeded and created a scalable solution. Since the use of Typescript among JS developers is opinionated I'll try to share also how not to use Typescript.