TypeScript adoption it's been a reality in the last years. This presentation is going to be an explanation on how we can take advantage of TypeScript compiler to have a smooth migration from JavaScript to TypeScript. Maintaining big projects in JavaScript can be a hard task. Wouldn't be great if we could gradually migrate our applications to TypeScript? Having types and access to all features from the latest EcmaScript versions can help us scaling and maintaining our code. TypeScript compiler allow us to compile JavaScript code and at the same time takes advantage of definitions to make type checking. Using this features we can easily start migrating our code base to TypeScript over time avoid headaches.