In this chapter, we will build a chatbot application with Facebook's Messenger platform using a completely different stack from what we were using so far in this book. For our view layer, we will swap React with Angular 2. To query data from the server, we will use a query language GraphQL, and in addition to MongoDB, we will add the Cassandra database. We won't be able to cover all of the preceding technologies in a great depth in one chapter, but certainly exploring other technologies can only benefit us as full-stack developers.

First, we can start from the frontend by creating a simple Meteor app with implementing Angular 2 as our view layer with all the necessary tooling that we need. We will use TypeScript instead of ES6, which is the recommended (by the Angular team) way of writing Angular 2 apps. TypeScript is a superset of JavaScript that at the end transpiles into a plain JavaScript. That said, it is completely fine to...