Visa Inc. interview question

Round 1 Coding Questions: Write a program to count the number of binary 1s in a number. Example: For 7 → Output should be 3. Write a program to check whether the given input contains valid parentheses. SQL Question: List all employees whose salary is greater than the average salary of their respective department. Scala Theory Question: What is implicit in Scala? Spark Questions: How do you copy data from HDFS to the local file system? What is the command for spark-submit? What is the difference between reduceByKey and groupByKey? What happens during a broadcast join in Spark, and how does it reduce shuffling? What happens when we use the collect() action in Spark? How do you define the minimum and maximum number of executors in Spark?