firebase-functions

```

functions/

├── src/

│ ├── index.ts # Function exports

│ ├── admin.ts # Firebase Admin SDK init

│ ├── backfill/ # Data migration scripts

│ ├── commentSuggestion/ # AI comment features

│ ├── commentings/ # Comment activity tracking

│ ├── notifications/ # Push notification functions

│ ├── postings/ # Post activity tracking

│ ├── replyings/ # Reply activity tracking

│ └── shared/ # Shared utilities

```

```typescript

import { onDocumentCreated } from 'firebase-functions/v2/firestore';

import admin from '../admin';

import { Post } from '../types/Post';

export const createPosting = onDocumentCreated(

'boards/{boardId}/posts/{postId}',

async (event) => {

const postData = event.data?.data() as Post;

const { boardId, postId } = event.params;

if (!postData) {

console.error('No post data found.');

return null;

}

try {

await admin.firestore()

.collection('users')

.doc(postData.authorId)

.collection('postings')

.add(postingData);

console.log(Created posting for user ${postData.authorId});

} catch (error) {

console.error('Error writing posting:', error);

}

return null;

}

);

```

Don't throw - let function complete gracefully:

```typescript

try {

await admin.firestore().collection('...').add(data);

console.log(Successfully created ${resourceType});

} catch (error) {

console.error(Error creating ${resourceType}:, error);

// Don't throw - function should complete

}

return null;

```

```bash

cd functions && npm install # Install deps

cd functions && npm run build # Compile TypeScript

cd functions && npm test # Run Jest tests

```