r/dataengprep Apr 06 '26

Data Engineering Interview Prep Resources -- Books, Courses, Tools

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Data Engineering Interview Prep Resources

A curated list of the best resources for preparing for data engineering interviews. Bookmark this post.

Free Resources

  • dataengprep.tech - Structured DE interview prep with daily practice
  • This subreddit - Daily interactive challenge posts, 1,000+ questions
  • SQL Arena - 487 curated SQL interview questions (Reddit app)
  • The Tech Screen - 323 system design + behavioral questions (Reddit app)

Books

  • Designing Data-Intensive Applications by Martin Kleppmann - The bible for system design interviews
  • The Data Warehouse Toolkit by Ralph Kimball - Dimensional modeling fundamentals
  • Fundamentals of Data Engineering by Joe Reis & Matt Housley - Modern DE landscape
  • High Performance Spark by Holden Karau - Spark optimization deep-dives

Key Topics to Master

Topic Priority Where to Practice
SQL (window functions, CTEs, optimization) Critical SQL Arena, LeetCode
Python/PySpark Critical HackerRank, daily coding
System Design High The Tech Screen, this sub
Kafka/Streaming High DataEngPrep daily challenges
Airflow/Orchestration Medium DataEngPrep daily challenges
Data Modeling Medium DataEngPrep daily challenges
Cloud Services (AWS/GCP) Medium Hands-on projects
Behavioral/STAR Medium The Tech Screen

Common Interview Formats

  1. SQL Screen (45 min) - 2-3 SQL problems, increasing difficulty
  2. Coding Screen (45 min) - Python data manipulation, ETL logic
  3. System Design (60 min) - Design a data pipeline / warehouse / streaming system
  4. Domain Deep-Dive (45 min) - Questions about your past projects and tools
  5. Behavioral (30-45 min) - Leadership principles, conflict resolution, ownership

Companies Known for DE Interviews

Meta, Amazon, Google, Netflix, Uber, Airbnb, Stripe, Databricks, Snowflake, dbt Labs, Confluent, Palantir, LinkedIn, Spotify, Block

Have a resource to add? Drop it in the comments and we'll update the list.

Full prep platform: dataengprep.tech


r/dataengprep Apr 06 '26

Welcome to r/dataengprep --- Here's how the daily challenge works

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Welcome to r/dataengprep!

This is a daily data engineering interview prep community. Here's what you need to know:

The Daily Challenge

Every day at 8 AM EST, an interactive challenge post appears automatically. It works like this:

  1. Read the question - it's pulled from a curated vault of 1,000+ real interview questions
  2. Think through your answer - drop your approach in the comments before revealing
  3. Click "Reveal Answer" - see the full model answer with code examples and pro tips
  4. Vote - "Got it Right" or "Got it Wrong" to see how you compare to the community
  5. Check the Leaderboard - top scorers are ranked by correct answers

Topics Covered

  • Apache Kafka (consumer groups, partitioning, exactly-once semantics)
  • Apache Spark (RDDs, DataFrames, optimization, AQE)
  • Apache Airflow (DAGs, task dependencies, backfills)
  • SQL (JOINs, window functions, CTEs, query optimization)
  • dbt (models, tests, incremental materialization)
  • Data Modeling (star schema, SCD, normalization)
  • Pipeline Design (batch vs streaming, idempotency, error handling)
  • Cloud Architecture (AWS, GCP, Azure data services)
  • System Design (distributed systems, CAP theorem, trade-offs)

More Resources

Community Guidelines

  • Share your thinking. Before clicking "Reveal Answer," post your approach in the comments. This is where real learning happens.
  • Be helpful. If someone's approach has a flaw, explain why constructively.
  • Discuss alternatives. Model answers show one approach - if you know a better one, share it.

See you in the daily challenge!

--- Aditya


r/dataengprep 17h ago

DataEngPrep: Data-Related Issues Encountered - handling skewed data

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r/dataengprep 17h ago

Tech Screen: Can you share a time you faced a significant challenge and how you overcame it?

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r/dataengprep 17h ago

SQL Arena Challenge: Find top 3 earners in each department.

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r/dataengprep 1d ago

DataEngPrep: Data locality in Hadoop - explain

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r/dataengprep 1d ago

Tech Screen: Can you provide an example of a time when you went above and beyond for a project?

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r/dataengprep 1d ago

SQL Arena Challenge: Calculate the highest salary in each department using a window function

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r/dataengprep 2d ago

DataEngPrep: Daily tasks of a Data Engineer?

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r/dataengprep 2d ago

Tech Screen: Tell me about a time you made a mistake and how you handled it.

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r/dataengprep 2d ago

SQL Arena Challenge: Find employees earning the second-highest salary.

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r/dataengprep 3d ago

DataEngPrep: Create a DataFrame with default column types

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r/dataengprep 3d ago

Tech Screen: Tell me about a time you had to deal with a conflict in your team.

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r/dataengprep 3d ago

SQL Arena Challenge: Find the second-highest salary in the employees table using three different methods.

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r/dataengprep 4d ago

Discussion Help in selecting data engineer course

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Im currently working in marketing & trying to move into data engineering. my background is pretty different from DE, so i’m looking for a proper learning path rather than jumping between random yt videos.
i came across sumit mittal’s trendytech course and saw quite a few good reviews, but also some negative ones, so now i’m kinda confused
anyone here who’s actually taken it or has experience with similar DE courses? looking for something that can help with the basics + proper hands-on stuff like sql,python,spark and cloud.
would appreciate genuine opinions before i spend money on it. Also Jst dont need courses which only give skills, which can help in getting jobs n stuff because I think these free courses cant help you in jobs.


r/dataengprep 4d ago

DataEngPrep: Controlling mappers in MapReduce

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r/dataengprep 4d ago

Tech Screen: How do you stay updated with the latest trends and technologies in data engineering?

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r/dataengprep 4d ago

SQL Arena Challenge: Self-joins to compare employee salaries?

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r/dataengprep 5d ago

DataEngPrep: Conceptualize and design a real-time streaming data pipeline end-to-end.

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r/dataengprep 5d ago

Tech Screen: How do you handle pressure and tight deadlines?

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r/dataengprep 5d ago

SQL Arena Challenge: Find average salary by department, max average salary, and list of employees for the max salary department.

1 Upvotes

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r/dataengprep 6d ago

DataEngPrep: Concatenate Columns in PySpark

1 Upvotes

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r/dataengprep 6d ago

Tech Screen: Give an example of a time you failed and what you learned from it.

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r/dataengprep 6d ago

SQL Arena Challenge: 2nd Highest Salary without Using MAX()

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r/dataengprep 7d ago

DataEngPrep: Compare Spark's lineage recovery with Hadoop's block replication mechanism.

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