Real questions from top companies · hard
Explain the difference between TriggerDagRunOperator and ExternalTaskSensor in Airflow.
Explain the difference between coalescing and repartitioning in Spark
Explain the differences between Spark's shuffle and broadcast join. When would you use each?
Explain the impact of Vacuum and Analyze operations on performance.
Explain the role of DAGs (Directed Acyclic Graphs) in Spark.
Explain your choice of streaming framework (Kafka, Spark Streaming, etc.).
Fault Tolerance in Spark vs. Hadoop?
Given a DataFrame with columns id and name, add a new column department: If id < 100 assign HR, if id >= 100 and id < 200 assign admin.
Given two DataFrames, perform specified data transformations and store the result in a new DataFrame
GroupByKey vs ReduceByKey – Differences and performance implications?
Handling Skewness in Data - salting, broadcast join
Handling custom data types in Spark
Have you worked with UDFs in Spark? When do you use them, and how do they differ from built-in functions?
Have you worked with data compaction in Delta Lake?
How can Docker be used to scale streaming data applications?
How can Spark help in optimizing ingestion?
How can lifecycle management policies complement ADF for this task?
How did you handle data ingestion and processing for large datasets?
How do Delta Live Tables ensure data quality during transformations?
How do Delta Tables handle large-scale data updates efficiently?
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