TypeScript forever changed how we write servers in Node.js. A tool that guarantees application correctness feels amazing. Except, that is only one end of the story. There are also the inputs our server receives and the systems it interacts with, which play a role when our code runs in production. Since TypeScript is a static type checker, it can only help with what it sees: our code. So how can we reconcile our runtime with TypeScript? In this lightning talk, I’ll show how our team achieved that for our Express servers with the help of some great open-source libraries that you can use as well.