Data Engineer Interview Questions and Answers
Ques 16. What is Apache Spark, and how is it used in data processing?
Apache Spark is an open-source, distributed computing system used for big data processing and analytics. It supports in-memory processing and provides APIs for various programming languages.
Example:
Using Apache Spark to process large-scale log data and extract meaningful insights in near real-time.
Ques 17. Explain the concept of data deduplication in data engineering.
Data deduplication involves identifying and removing duplicate records or data points within a dataset, improving data quality and storage efficiency.
Example:
Identifying and eliminating duplicate customer records in a CRM database.
Ques 18. What are NoSQL databases, and when would you choose to use them over traditional relational databases?
NoSQL databases are non-relational databases designed for scalability, flexibility, and handling large amounts of unstructured or semi-structured data. They are chosen when dealing with high-volume, distributed, and dynamic data.
Example:
Using a NoSQL database to store and retrieve JSON documents in a web application.
Ques 19. How do you handle data skew in a distributed computing environment?
Data skew occurs when certain partitions or shards have significantly more data than others. Techniques to handle data skew include re-partitioning, data pre-processing, and using advanced algorithms for data distribution.
Example:
Re-partitioning a dataset based on a different key to distribute the data more evenly in a Spark job.
Ques 20. What is the role of data cataloging in a data ecosystem?
Data cataloging involves organizing and managing metadata about data assets in an organization. It helps in discovering, understanding, and governing data across the enterprise.
Example:
Using a data catalog to search for and understand the metadata of a specific dataset within an organization.
Most helpful rated by users: