Openingloading the content…

Loadingone moment…

Commerce, Travel & Marketplaces

Walmart

Retail / e-commerce · Data Engineering interview

DSA + SQL, then a Spark-heavy round (OOM, partitionBy vs bucketBy) and a Staff-DE system-design finale.

Cloud / platform

GCP + Azure + on-prem; Spark, Kafka, Hive

Reported difficulty

Not reported

SQLPythonSparkPySparkKafka

Hiring process

Recruiter (45m)

Tech 1 (DSA + 2 SQL)

Tech 2 (Spark + design)

Staff DE (~1h45m, design)

Offer

Round-by-round breakdown

SQL

High confidence

Find the top 5 selling products per category for the last month
Window functions, joins (inner/outer/cross), aggregations, performance tuning

DSA / Python

Medium confidence

Medium–hard DSA; problem-solving on data structures + PySpark (Tech 1)

Spark

· centralHigh confidence

Optimize a Spark job failing due to OutOfMemory errors
Difference between partitionBy and bucketBy in Spark
Kafka concepts

System & pipeline design prompts

Design a data pipeline to ingest real-time clickstream data from Walmart.com
Design an event-driven system (Staff round)

Prep — high priority

Spark internals (OOM fixes, partitionBy vs bucketBy, skew, PySpark)
SQL (top-N per group, window, joins, optimization)
System design (real-time clickstream, event-driven); DSA medium–hard

Prep — medium priority

Kafka
Data modeling/warehousing
Behavioral

Rejection patterns

Shallow Spark internals (OOM, partitionBy vs bucketBy)
Weak system design at Staff round
Cannot translate business logic to efficient SQL
DSA misses in Tech 1

Reported experiences

Data Engineer III

Rejection to offerFirst-hand

Recruiter → Tech 1 (DSA + 2 SQL window/joins/opt + PySpark) → Tech 2 (Spark optimization, OOM fix, partitionBy vs bucketBy, Kafka, system design) → Staff-DE final (event-driven system design, ~1h45m) → HR. Real Qs: top-5 products/category; Spark OOM; partitionBy vs bucketBy; Walmart.com clickstream pipeline.

Rehearse for Walmart

Answered questions on what Walmart actually asks — each with the short answer, the answer that gets you rejected, and the follow-up.

Then build one and have it reviewed: design a daily orders pipeline or model a marketplace. No account.

All interview experiences