Walmart Labs Interview Questions, Process, and Tips

Round: HR Interview
Experience: 1. Why do you want to join Walmart Labs?

2. What are the biggest challenges faced by me in my current job.

Round: Test
Experience: There were 2 coding questions given in this round. The platform used is Hacker rank and we have to complete both questions in their office only in 1 hour. Usage of internet is strictly prohibited.
1. Find Maximum sum in an array such that no 2 elements are adjacent. In this, 1 more condition was also there that first and last elements should also not be taken together. This question was modification of
-----. In a cartesian plane, there are N tanks and M objects placed. Tanks can fire in 4 directions (N, S, E, W). Position of tanks and objects are given as input and are fixed. We have to find a way to give directions to N tanks such that they will not hit any object and any other tanks. If a tank can fire in 2 directions, then a direction whose ASCII code is lesser will be given preference.Example:-
Input :-
N=2
M=3Position of tanks
(0,0)
(1,1)Position of Objects
(0,2)
(0,-2)
(-2,0)Direction of N tanks should be :-
(0,0) E -> This tank should fire in east direction
(1,1) E -> This tank can fire in all 4 directions. Since E has least ASCII code in all 4 of them, so E

Round: Technical Interview
Experience: 1. Design a complete Railway Reservation System. Following things are checked in code:-
a. Object Oriented Programming
b. Design Patterns used(if any)
c. Are use cases are optimised or not?
2. Question on LRU cache implementation

Round: Technical Interview
Experience: 1. Design a data structure which provides following APIs:-
a. insert element in O(1)
b. delete an element in O(1)
c. find a random element in O(1)
2. Some questions on Java basics.
3. Some discussion on projects done in current job.
4. Got 1 feedback that my knowledge of Java is not so good. So, if we hire you, then what will be your strategy to improve on your Java skills.

College Name: NA

Round: Test
Experience: The complete selection procedure consisted of 1 online round and 4 face to face interviews. First online round had 10 MCQs with negative marking followed by 3 quality programming questions.

Round: Technical Interview
Experience: In technical rounds, none were straight forward question and you can expect complex problems of DP and Greedy concepts. They also asked me to solve some real time problems given large data and all.

Round: MANAGERIAL ROUND
Experience: Managerial round consisted of few very basic questions followed by my expectations from company, profile I seek etc

Round: HR Interview
Experience: The HR round was also kind of similar. He first described his experience at Walmart and then asked me about my interests, family etc.

General Tips: If you want to get a good one, you need to practice. Good companies basically emphasizes much on Data Structures, Algorithms and OS concepts. So one must be very good at it.
But those concepts help once you reach the interview round which is generally after an online round. In the first online round, most of the questions are from C/C++ aptitude and then few are of general aptitude. One must be very quick at solving these problems. For practicing them, one can refer geeksforgeeks for C/C++ aptitude and some CAT book to see basics of probability, permutation and combination, Work/time concepts.
For data structures and Algorithm, first solve the book by Narsimha Karumanchi but don't try to see the solution directly. Try as much as you can before seeing the solution as it won't be a waste of time. It will further clarify much of your concepts.
After completing the book, start solving DS part of geeksforgeeks. Try to cover as much questions of trees and linked lists as possible. Also cover classical problems of Dynamic programming and greedy algorithms.
Apart from being good at designing algorithms for problems, one must be able to write a working code for it in either of C/C++/Java. This is very important because most of the good companies introduces 2-3 programming questions in the first round itself. Even in interview, they ask to write the program on paper. Hence, try to practice coding too along with studying the above referenced materials.
It felt awesome when I got selected for Walmart Labs. The interviews were really the best one I faced. I was quite chilled out during the interviews as I already had an offer from Amazon. That may be the reason I was able to solve some of the really good questions. Overall, the experience was quite challenging and amazing.
Skill Tips: For data structures : First go through "Data Structures and Algorithms made Easy" by Narsimha Karumanchi.
For improving coding skills, try to program few random questions of trees and linked list while studying there concepts. Then practice some questions from sites like codechef or codeforces and also try to participate in the competitions that take place on these sites.
For Operating Systems, just go through the book written by "S Galvin" and try to clear concepts of memory management part.
Apart from these main topics, just have a glance at these few topics:-
Database : Basic Queries, Indexing, Transaction.
OOP : Definition with understanding of four features of OOPs.


Skills:
College Name: NIT Surathkal

Round: Resume Shortlist
Experience: People having GPA above 7 got shortlisted.

Round: Test
Experience: Test Question Topics

Round: Test
Experience: There were three coding questions out of which one was adhoc and two were of Dynamic Programming.
Duration: 1 hour 30 minutes
Total Questions: 3

Round: Technical Interview
Experience: Questions related to Data Structures were asked. Then I was asked questions from area of interest.
Tips: Make sure your concepts of subjects that you mention in AOI should be clear.

Round: Technical Interview
Experience: Questions related to Operating Systems were asked. Then some questions on Binary trees data structure followed.

Round: Technical + HR Interview
Experience: It was tech cum HR round. There were basic questions asked. Then questions on DBMS were asked.

Round: HR Interview
Experience: Basic HR questions.

Skills: Confidence, Inter Person Communication Skills, Algorithm, Data Structures, Operating Systems, Knowledge About Database Managements Systems
College Name: NIT ALLAHABAD