Deployment on Railway

Deployment guide for Express and MongoDB on Railway.

1. Create a Railway Account

Select Create > Database
Choose MongoDB
Railway will provision the database automatically.
Copy the MongoDB connection string displayed in the database settings tab. This URL is required to connect your Express backend to the MongoDB cluster.

Click Create
Choose Deploy from GitHub
Select the Express repository you want to deploy
Select the newly created project node for your repository
Open the Settings tab and configure deployment properties such as the targeted production branch.
Open the Variables tab and register all necessary environment variables, including the MONGODB_URI connection string retrieved previously. For example:
- MONGODB_URI: mongodb+srv://<username>:<password>@<cluster-url>/<database-name>?retryWrites=true&w=majority
- Ensure you replace placeholders (<username>, <password>, <cluster-url>, <database-name>) with your actual credentials.

Note: If deploying the project developed through this course's earlier guides, keep the following configuration adjustments in mind:

In package.json, verify you have scripts to compile TypeScript to JavaScript:
package.json
```
"scripts": {
  "build": "tsc",
  "start": "node dist/index.js"
}
```
Use dotenv to manage environment variables. Install the dependency with:
```
npm install dotenv
```
In your main entrypoint (e.g., index.ts), initialize environment variables at the top of the file:
Link your Express Repository
```
import dotenv from 'dotenv';
dotenv.config();
```
Configure CORS appropriately if frontend clients will consume your API. Install cors:
```
npm install cors
npm install -D @types/cors
```
And configure in your application:
Link your Express Repository 2
```
import cors from 'cors';
app.use(cors());
```

Open the Settings tab.
Under the Networking section, select Generate Domain.
Railway will provision a public URL allowing global access to your deployed Express application.