04A Spark job that used to finish in minutes now takes hours. How do you diagnose and fix it?▼hardDatabricksSnowflakeMicrosoft2 repliesunlockedThe Databricks-flavored performance question. What interviewers want is a candidate who heads straight for the usual suspects (skew, shuffle, spill) through the Spark UI rather than guessing. Here is the diagnostic order and the fixes that genuinely move the needle.Open full answer →
23What is data skew in a distributed job (Spark), and how do you fix it?▼hardDatabricksAmazonMeta1 replies◆ premiumThe number-one cause of mysteriously slow Spark jobs: one partition handles most of the work while the rest idle. The signal is reading the symptom (a few straggler tasks) and reaching for the right fix, salting, broadcast, or AQE.Open full answer →
