General Data Engineer interview prep
1 live role at Zain Placement ConsultancyData pipelines, SQL, big-data tools and warehousing — the data-engineering interview for analytics, fintech and product teams building data platforms.
Typical Data Engineer interview rounds
- 1 SQL & data modelling. Complex queries, window functions, star vs snowflake schema design.
- 2 Big data & pipelines. Spark, Hadoop, ETL/ELT design and batch vs streaming.
- 3 Coding round. Python/Scala data manipulation and DSA basics.
- 4 System design. Design an end-to-end data pipeline or warehouse.
Commonly-asked Data Engineer questions
- What is the difference between ETL and ELT, and when do you use each?
- Explain the difference between a data warehouse, a data lake and a data mart.
- What is the difference between a star schema and a snowflake schema?
- How does Apache Spark work, and what is an RDD vs a DataFrame?
- Explain the difference between batch processing and stream processing.
- What is partitioning and bucketing in Hive, and why do they matter?
- How do you handle slowly changing dimensions (SCD types 1, 2 and 3)?
- What is data normalisation, and when would you denormalise for analytics?