Traditional Backend:

• Requires setting up and maintaining servers
• Need to write API endpoints manually
• Database management and optimization
• Manual scaling and infrastructure management
• Separate authentication implementation
• Custom real-time functionality implementation

Firebase:

• Serverless - no server management needed
• Pre-built APIs and SDKs
• Managed databases with automatic scaling
• Built-in authentication system
• Real-time synchronization out of the box
• Pay-as-you-use pricing model
• Faster development and deployment

Firebase Authentication supports multiple sign-in methods:

Social Providers:

• Google
• Facebook
• Twitter
• Apple
• Microsoft
• Yahoo
• GitHub

Traditional Methods:

• Email/Password
• Phone number (SMS verification)
• Anonymous authentication

Enterprise:

• SAML
• OpenID Connect (OIDC)
• Custom token authentication

// Initialize Firebase Auth
import { auth } from './firebase-config';
import { createUserWithEmailAndPassword, signInWithEmailAndPassword } from 'firebase/auth';

// Sign up
const signUp = async (email, password) => {
  try {
    const userCredential = await createUserWithEmailAndPassword(auth, email, password);
    console.log('User created:', userCredential.user);
  } catch (error) {
    console.error('Sign up error:', error.message);
  }
};

// Sign in
const signIn = async (email, password) => {
  try {
    const userCredential = await signInWithEmailAndPassword(auth, email, password);
    console.log('User signed in:', userCredential.user);
  } catch (error) {
    console.error('Sign in error:', error.message);
  }
};

Firestore uses a hierarchical data model:

Documents:

• Similar to JSON objects
• Contain fields with values
• Have unique IDs within collections
• Can contain subcollections

Collections:

• Containers for documents
• Cannot contain other collections directly
• Automatically created when first document is added

Structure Example:

users (collection)
  ├── user1 (document)
  │   ├── name: "John Doe"
  │   ├── email: "john@example.com"
  │   └── posts (subcollection)
  │       └── post1 (document)
  │           ├── title: "My First Post"
  │           └── content: "Hello World"
  └── user2 (document)
      ├── name: "Jane Smith"
      └── email: "jane@example.com"

Cloud Functions are serverless functions that run backend code in response to events.

Main Use Cases:

• Database triggers: Respond to Firestore/Realtime Database changes
• Authentication triggers: Handle user creation/deletion
• HTTP triggers: Create REST APIs
• Storage triggers: Process uploaded files
• Scheduled functions: Cron-like scheduled tasks
• Third-party integrations: Connect with external APIs

Benefits:

• No server management
• Automatic scaling
• Pay only for execution time
• Integrated with Firebase services