HackerRank Data Engineer Interview Questions
& Process
Real candidates share what happened, how many rounds they had,
and how the experience turned out.
Based on 5 interview experiences · FREE TO READ
Candidate interview experiences
First-hand accounts from people who interviewed at HackerRank.
HackerRank
Data Engineer
Senior Difficult Positive experience No offer 2 rounds
Interview process
Technical screen Onsite
Interview formats
Coding Technical
The interview process included a coding round on HackerRank using Scala, though I was able to use PySpark after talking to the recruiter. Then there was an interview focusing on core Spark concepts, data engineering, and the projects I've worked on.
Confirmed questions3 questions
- How to optimize Spark execution time?
- Tell me about resolving slow Spark code execution.
- Can you explain Spark UI?
HackerRank
Data Engineer
Mid Average Negative experience No offer 5 rounds
Interview process
Take home Technical screen Onsite Technical screen Technical screen
Interview formats
Coding Technical System Design Coding Coding
Applied on LinkedIn and got an online assessment invite after 2 days. First was the OA round with a long spark scala question and some MCQs. Then came the Design Round, asking to build a data pipeline from three sources (csv, clickstream, APIs) for the data science team. Next was the HM round, discussing my projects, team fit, and Spark Internals, operations on Spark SQL queries. Fourth was the Spark Round, starting with a long Spark question involving two files, filters, joins, and selects, followed by medium to complex SQL queries. Finally, the Solution Engg Round, where I had to discuss my recent project's end-to-end flow and answer basic to medium python questions like flattening JSON and counting letters, plus some SQL queries.
Confirmed questions4 questions
- Tell me about Spark internals and operations/transformations, and how to optimize them.
- Write advanced SQL queries using CASE WHEN, RANK, and LEAD/LAG functions.
- How would you flatten a nested JSON structure using Python?
HackerRank
Data Engineer
Entry Average Negative experience No offer 1 round
Interview process
Technical screen
Interview formats
Coding
I had a Hackerrank screening test with 2 coding questions. The first was a Pyspark question that required detailed implementation in an auto-fill IDE similar to VS Code. The second was an SQL question, which was good, but had a major issue with output formatting. It needed '0' as '0.00', but the auto-formatting changed it to '.00', causing my correct solution to be rejected. This formatting issue led to my disqualification from the screening test, even though my logic was sound.
Confirmed questions2 questions
- Write Pyspark code for data frame transformation.
- Solve the SQL problem using window functions.
HackerRank Data Engineer Interview Questions
Quoted word for word from HackerRank interview reports.
“In Python, how can you display only the letters that appear more than once in a given string?”
Read reports →“How would you flatten a nested JSON structure using Python?”
Read reports →“Write Pyspark code for data frame transformation.”
Read reports →“Solve the SQL problem using window functions.”
Read reports →“Implement the solution using Scala”
Read report →“How to optimize Spark execution time?”
Read report →“What are the different join types and what are their edge cases?”
Read report →“Write advanced SQL queries using CASE WHEN, RANK, and LEAD/LAG functions.”
Read report →“Can you explain the basics of Hadoop?”
Read report →Formats, difficulty and experience
Across all 5 HackerRank interview reports.