I interviewed at Walmart Labs in February 2020.

There were 4 interviews: 3 technical and 1 with the hiring manager.

First Round:

• Find the maximum element from a huge number of elements, which can be solved using a max heap.
• Difference in array elements (can contain duplicates) when rotated.

Second Round:

• All Java basics, including multithreading, synchronization, HashMap, etc.
• Balance brackets in an expression.
• Generate all possible substrings from a given string.
• How an AVL tree works.

Round 3:

• Questions on current project architecture.
• Difference between columnar vs. row-based database storage.
• Maximize profit from the given stocks.

Round 4:

• General discussion about current salary and notice period with the hiring manager.

My all rounds went well, and the hiring manager told me the feedback was positive and HR would contact me. However, HR did not contact me. After chasing HR for 3-4 days, she said there was some change in the requirement and she was not sure whether the position was relevant anymore. She said she would get back to me in a few days. I waited for another week and, after contacting HR, she said the feedback was negative.

A complete waste of time. This is my second bad experience with Walmart; they are conducting interviews, and they are not even sure whether they have the requirement or not.

Find the maximum element from a huge number of elements, which can be solved using a max heap.

Difference in array elements (can contain duplicates) when rotated.

Balance brackets in an expression.

Generate all possible substrings from a given string.