Role
Data Engineer
Real interview questions with expert answers, plain-English explanations, and practical examples. (43 questions)
Deloitte
Data Engineer
Data Structures & Algorithms
Explain the HyperLogLog algorithm, and how would a data engineer use it to estimate unique counts for massive datasets?
Cognizant
Data Engineer
Data Structures & Algorithms
Explain the differences between Bloom filters and Count-Min sketches, and when would a data engineer use each for approximate analytics?
ServiceNow
Data Engineer
Performance Optimization
A critical batch data pipeline is experiencing significant delays. How would you diagnose and optimize its performance?
LTIMindtree
Data Engineer
Message Queues
How do message queues handle consumer scaling and failure scenarios in a high-throughput data pipeline?
Flipkart
Data Engineer
Performance Optimization
How would you optimize a large-scale ETL pipeline for both cost and speed in a cloud environment?
ServiceNow
Data Engineer
Data Structures & Algorithms
How does a segment tree efficiently handle range queries and updates, and what are its practical applications in data engineering?
Zomato
Data Engineer
Security
How would you secure a data lake environment, considering data at rest, in transit, and access control for various users?
VMware
Data Engineer
Databases
How do database sharding and partitioning differ, and when would you implement each for scalability?
Adobe
Data Engineer
Performance Optimization
How do you approach optimizing a data pipeline for both throughput and latency, especially with streaming data?
IBM
Data Engineer
System Design