ETL
Extract, transform, load: the pattern of pulling data from source systems, cleaning it, and loading it into a warehouse.
What it tells you about a developer
ETL on a profile means the person builds or maintains data plumbing. The order of the letters carries a real distinction: classic ETL leans toward data engineering in code, while ELT with transformations in the warehouse leans toward analytics engineering in SQL. Asking which tools they used settles which side of the line they work on.
ETL names the three steps of moving data for analysis: extract it from sources like an app database or Stripe, transform it into clean consistent tables, and load it into a warehouse. The modern variant, ELT, loads the raw data first and transforms it inside the warehouse, which is the pattern tools like dbt serve.