Question 1

What's the difference between ETL and ELT?

Accepted Answer

In ETL, data is transformed before it's loaded into the destination using a separate processing engine. In ELT, raw data is loaded into the destination first, and transformation happens afterward using the destination's own compute power, often as SQL.

Question 2

What's the difference between a data warehouse and a data lake?

Accepted Answer

A data lake stores raw data without requiring a predefined schema before loading (schema-on-read), while a data warehouse requires structured data conforming to a predefined schema before loading (schema-on-write) and is optimized for fast analytical queries.

🛠️ Data EngineerInterview Questions

🛠️ Data Engineer
Interview Questions