Sure! I can help you create a step-by-step guide to building a secure and scalable authentication system using TypeScript with Node.js, MongoDB, and Express. Step 1: Setting up the Project First, let's create a new project directory and initialize it with npm. Navigate to the directory where you want to create your project and run the following command: bash Copy code mkdir auth-system cd auth-system npm init -y Next, let's install the required dependencies: bash Copy code npm install express cors morgan helmet bcrypt jsonwebtoken dotenv mongoose npm install -D typescript @types/node @types/express @types/mongoose ts-node nodemon This will install Express, Cors, Morgan, Helmet, Bcrypt, JsonWebToken, Dotenv, and Mongoose as dependencies, as well as TypeScript, ts-node, and Nodemon as development dependencies. Next, let's set up the project structure. Create a new src directory and add a server.ts file to it: bash Copy code mkdir src touch src/server.ts Inside server.ts, add the following code: typescript Copy code import express from "express"; const app = express(); app.get("/", (req, res) => { res.send("Hello World!"); }); const port = process.env.PORT || 5000; app.listen(port, () => { console.log(`Server running on port ${port}`); }); This sets up a basic Express server that listens on port 5000 and responds with "Hello World!" when a GET request is made to the root endpoint. Now, let's add a start script to the package.json file: json Copy code "scripts": { "start": "nodemon src/server.ts", "build": "tsc", "test": "echo \"Error: no test specified\" && exit 1" }, This will allow us to start the server using the npm start command. Type "next" when you're ready to move on.