The Top 50 Data Engineering Interview Questions and Answers in 2025
Are you preparing for a data engineering interview in 2025? Whether you’re a fresher or an experienced professional, mastering these top 50 data engineering interview questions will help you land your dream job.
In this guide, we’ll cover technical, scenario-based, and behavioral questions along with detailed answers. We’ve also included graphs, real-world examples, and expert tips to make your preparation easier.
Let’s dive in!
Why Data Engineering Interviews Are Challenging in 2025?
Data engineering is evolving rapidly with AI, cloud computing, and big data technologies. Companies now expect candidates to have hands-on experience with:
Real-time data processing (Kafka, Spark Streaming)
Cloud platforms (AWS, GCP, Azure)
Advanced SQL & NoSQL databases
Data pipeline orchestration (Airflow, Dagster)
To stand out, you must be well-prepared. Below, we’ve categorized the top 50 data engineering interview questions into key topics.
Basic Data Engineering Interview Questions (2025)
1. What is Data Engineering?
Answer: Data engineering involves designing, building, and maintaining systems that collect, store, and process large-scale data for analytics and machine learning.
2. What’s the Difference Between a Data Engineer and a Data Scientist?
Answer:
| Data Engineer | Data Scientist |
|---|---|
| Builds data pipelines | Analyzes data |
| Focuses on infrastructure | Focuses on ML models |
| Works with ETL/ELT | Works with statistical models |
3. Explain the ETL Process.
Answer: ETL (Extract, Transform, Load) is a data integration process where:
Extract: Pull data from sources (APIs, databases).
Transform: Clean, filter, and structure data.
Load: Store data in a warehouse (Snowflake, BigQuery).
Intermediate Data Engineering Interview Questions (2025)
4. What Are the Best Data Warehousing Solutions in 2025?
Answer: The top data warehouses in 2025 are:
Snowflake (Cloud-native, scalable)
Google BigQuery (Serverless, fast queries)
Amazon Redshift (AWS optimized)
5. How Do You Optimize a Slow-Running SQL Query?
Answer:
Use indexes on frequently queried columns.
Avoid
SELECT *– fetch only needed columns.Partition large tables for faster scans.
6. What is a Data Lake vs. Data Warehouse?
Answer:
| Data Lake | Data Warehouse |
|---|---|
| Stores raw, unstructured data | Stores processed, structured data |
| Schema-on-read | Schema-on-write |
| Used for big data & AI | Used for BI & reporting |
Advanced Data Engineering Interview Questions (2025)
7. Explain Real-Time Data Processing with Apache Kafka.
Answer: Kafka is a distributed streaming platform used for:
Real-time analytics (fraud detection)
Event sourcing (user activity tracking)
Data pipelines (microservices communication)
8. How Do You Handle Missing Data in a Pipeline?
Answer: Strategies include:
✔ Imputation (fill with mean/median)
✔ Deletion (remove incomplete rows)
✔ Flagging (mark missing values)
9. What Are the Best Data Orchestration Tools in 2025?
Answer:
Apache Airflow (Python-based, widely used)
Dagster (Modern, metadata-rich)
Prefect (Flexible, cloud-native)
Scenario-Based Data Engineering Interview Questions (2025)
10. How Would You Design a Scalable Data Pipeline for an E-Commerce Company?
Answer:
Ingestion: Use Kafka for real-time order data.
Processing: Spark for aggregations.
Storage: Snowflake for analytics.
Monitoring: Airflow alerts for failures.
Behavioral Data Engineering Interview Questions (2025)
11. Describe a Time You Fixed a Broken Data Pipeline.
Answer (STAR Method):
Situation: Pipeline failed due to schema change.
Task: Debug and restore data flow.
Action: Used logging and validation checks.
Result: Reduced downtime by 90%.
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Conclusion
Mastering these top 50 data engineering interview questions will boost your confidence and help you crack interviews in 2025. Focus on hands-on projects, cloud certifications, and real-world problem-solving to stay ahead.
Need more help? Check out our Data Engineering Career Guide for expert tips.
About the Author
Mudita Agarwal is a Social Media Executive at BrowseJobs.in, specializing in tech careers and interview preparation. With over 2 years of experience, she helps job seekers land top roles in data engineering, AI, and cloud computing.
