Bronze vs Silver vs Gold: What I Learned Building My Pipeline

When you read about the Medallion architecture, it sounds like a rigid set of rules. However, while building my Job Market pipeline, I learned that these layers solve highly practical problems regarding data state.

The Bronze Layer: The Safety Net

My Bronze layer takes the raw JSON dumped into Amazon S3 from the JobsPipe API and saves it as a Delta table. No transformations. No cleaning. If my downstream logic changes tomorrow, I don't need to re-query the API; I just re-process the Bronze data.

The Silver Layer: The Truth

This is where the heavy lifting happens. In Silver, I apply my six data quality checks, remove duplicates using PySpark, format timestamps, and flatten nested JSON. Silver represents a clean, queried state of reality.

The Gold Layer: The Business Value

Silver data is clean, but it's not optimized for a Databricks AI/BI dashboard. The Gold layer consists of 6 tables that group and aggregate the data. Instead of raw job rows, Gold tables contain specific metrics like skill co-occurrence and city demand, making dashboard queries incredibly fast.