Module Lead Software Engineer Interview Questions and Answers

Multithreading allows concurrent execution of multiple threads. Future and CompletableFuture are used for asynchronous programming.

• Multithreading enables parallel processing of tasks

• Future is used to represent a result that may not be available yet

• CompletableFuture is a subclass of Future that provides more flexibility and functionality

• CompletableFuture can be used to chain multiple asynchronous tasks

• CompletableFuture can also be used to handle exceptions and timeouts

Spark wordcount and sort in descending order with their number occurrence in dataframe

• Read text file into dataframe using spark.read.text()

• Split each line into words using split() function

• Use groupBy() and count() functions to count the occurrence of each word

• Sort the resulting dataframe in descending order using orderBy() function

• Show the resulting dataframe using show() function

Find the intersection point of two arrays of strings.

• Convert arrays to sets to find common elements

• Iterate through one array and check if element exists in the other array

• Use built-in intersection method in Python

• Sort arrays and use two pointers to find common elements

To create a stack from two queues, we need to use one queue for storing elements and the other for temporary storage.

• Push elements into the first queue

• When popping, move all elements except the last one to the second queue

• Pop the last element from the first queue and return it

• Swap the names of the two queues to make the second queue the first one