Wells Fargo Data Engineer Interview Questions and Answers

Finding smallest of 4 numbers without using >.< and min function in Java.

• Initialize a variable with the first number

• Compare it with the remaining numbers using if-else statements

• If a smaller number is found, update the variable

• Repeat until all numbers are compared

• The final value of the variable will be the smallest number

Code for palindrome checking

• Convert the input to lowercase to ignore case sensitivity

• Use two pointers, one at the start and one at the end of the string

• Compare the characters at both pointers and move them towards each other

• If all characters match, it's a palindrome

Javascript code to display 'Hello World!' on the webpage

• Create a new HTML file

• Add a script tag with 'type' attribute set to 'text/javascript'

• Inside the script tag, use document.write() to display 'Hello World!'

Swap two numbers without using a temporary variable.

• Use addition and subtraction to swap the values

• Use XOR operator to swap the values

• Use multiplication and division to swap the values

To add 2 tables, we need to use a join operation on a common column.

• Identify the common column between the tables

• Choose the appropriate join type (inner, outer, left, right)

• Write the SQL query to join the tables

• Example: SELECT * FROM table1 INNER JOIN table2 ON table1.column = table2.column

Union combines and removes duplicates, Union All combines all rows including duplicates.

• Union is used to combine the result sets of two or more SELECT statements and remove duplicates.

• Union All is used to combine the result sets of two or more SELECT statements and includes all rows, including duplicates.

• Union is slower than Union All as it has to remove duplicates.

• Union requires the same number of columns in all SELEC...read more

Being assigned a project with unrealistic deadlines and minimal guidance

• Received a project with tight deadlines and unclear requirements

• Struggled to meet the deadlines due to lack of guidance and support

• Had to work long hours and weekends to try to complete the project

• Learned the importance of clear communication and setting realistic expectations

Implement LRU cache

• LRU stands for Least Recently Used

• It is a cache eviction policy that removes the least recently used item

• It can be implemented using a doubly linked list and a hash map

• Newly accessed items are moved to the front of the list

• When the cache is full, the item at the end of the list is removed

Virtual memory is a memory management technique that allows a computer to use more memory than it physically has.

• Virtual memory uses a combination of RAM and hard disk space to store data.

• It allows programs to use more memory than is physically available.

• If a program tries to access memory that is not currently in RAM, it will be swapped in from the hard disk.

• Even if we had infinite RAM, virtual memory would still be n...read more

Find maximum length of subarray where max <= 2*min.

• Iterate through array and keep track of max and min values.

• Update max length when condition is met.

• Time complexity: O(n)

I have a strong background in software engineering and a passion for innovation, making me a valuable asset to HSBC.

• I have a proven track record of successfully delivering high-quality software solutions in previous roles.

• I am highly skilled in various programming languages and technologies, including Java, Python, and SQL.

• I have experience working in agile development environments, allowing me to adapt quickly to chan...read more