MongoDB Atlas

// 1. Sign up at https://cloud.mongodb.com
//    Create a project, then a cluster (M0 is free)
//    Region: pick the one nearest your application

// 2. Add a database user
//    Database Access -> Add New Database User
//    Username: app
//    Password: long random
//    Roles: readWrite on your DB only

// 3. Network access
//    Network Access -> Add IP Address
//    Production: lock to your VPC peering or private endpoint
//    Dev: add only your current IP, not 0.0.0.0/0

// 4. Connection string (SRV)
//    mongodb+srv://app:<password>@cluster0.xxxxx.mongodb.net/myapp?retryWrites=true&w=majority

// 5. Connect from Node
import { MongoClient } from 'mongodb';

const uri = process.env.MONGODB_URI;
const client = new MongoClient(uri, {
  serverSelectionTimeoutMS: 5000,
  maxPoolSize: 20,
});

await client.connect();
const db = client.db('myapp');
const users = db.collection('users');
await users.createIndex({ email: 1 }, { unique: true });

// 6. Useful Atlas features
//    - Performance Advisor: index suggestions from real queries
//    - Atlas Search: Lucene-backed full text search
//    - Triggers: serverless reactions to changes
//    - Backup: continuous PITR on dedicated clusters
//    - Online archive: tier cold data automatically

// 7. Cost gotchas on shared (M0/M2/M5)
//    - No backups beyond snapshot
//    - Limited connections (M0 = 500)
//    - Use only for dev or tiny side projects

// MongoDB Atlas — fully-managed; free tier available.
// Whitelist your IP, create a user, paste the connection string.