data engineering interview

It Ran in 10 Minutes Yesterday: How to Debug a Slow Spark Job and Fix Data Skew

September 24, 2026January 28, 2026 by Nikhil Aggarwal

Spark job suddenly slow? Learn to find data skew in the Spark UI and fix it with AQE, broadcast joins and salting. Real screenshots and interview answers.

Categories Apache Spark, Big Data Tags adaptive query execution, amazon emr, apache spark, broadcast join, data engineering interview, pyspark, salting, spark data skew, spark performance tuning, spark ui

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