ETL Pipeline: REST API to PostgreSQL

## ETL Pipeline Setup

1. **Schedule**: Runs every hour.
2. **Fetch**: Gets JSON data from REST API.
3. **Filter**: Removes inactive items or items with 0 price.
4. **Transform**: Maps API fields to DB schema and adds timestamp.
5. **Load**: Upserts data into PostgreSQL based on SKU.

**Error Handling**: If any node fails, a Slack notification is sent.