Walmart Software Engineer Interview Questions + Guide in 2024

Being the global leader in the retail industry, Walmart continually sets the standards for customer-centric solutions and innovation. Their commitment to enhancing the customer experience through technology increases the demand for software engineers.

In this guide, we’ll delve into the step-by-step hiring process for the Walmart software engineer role, some commonly asked questions in the interview, and tips on how to ace the interview.

If you are considering applying at Walmart, then this guide is especially for you.

The Walmart Software Engineer Interview Process is designed to find the best tech talent who not only excel in coding and problem-solving but also thrive in collaborative environments.

The hiring process usually has the following stages:

Resume Review and Initial Screening

Submit your application with an updated resume at the Walmart Careers portal. The recruiting team will review your application, and if it stands out, you will be contacted for an initial screening. They will then discuss your background, experience, skills, and interest in the role.

Online Technical Assessment

Next up, you’ll go under a technical assessment if qualified. This may include some MCQ questions followed by coding challenges. This round focuses on your understanding of the fundamentals of CS, such as OOP, algorithms, operating systems, and computer networks. The technical assessment is often through Karat and you could be asked to choose two topics of your choice for the assessment. The difficulty level of these challenges ranges from easy to hard.

Technical Phone Interview

After successfully clearing the technical assessment, you’ll get an email to schedule the technical phone interview. In this round, you may have discussions with one or more members of the technical team. They will ask questions related to algorithms, data structures, and your approach to problem-solving. Showcasing clear communication and coding skills is important in this stage.

Behavioral and Cultural Fit Interview

In addition to technical skills, Walmart values candidates who align with the company’s culture and values. In this round, expect questions related to teamwork, collaboration, and how you approach challenges. This step assesses your fit within the broader organizational environment of Walmart.

Typically, interviews at Walmart vary by role and team, but commonly Software Engineer interviews follow a fairly standardized process across these question topics.

During Walmart’s Software Engineer interviews, candidates face a range of questions. These questions measure their aptitude for handling pressure, teamwork, and staying updated on emerging technology.

The challenges involve practical scenarios in optimizing code, implementing algorithms, manipulating strings, and designing data structures. Proficiency in SQL for data analysis, understanding machine learning models, and creating efficient software solutions is also important.

Read through the full list below to gain a better understanding of the Walmart software engineer interview questions:

1. How do you deal with pressure and stress?

Working as a software engineer at Walmart can include handling complex projects, tight deadlines, and high expectations. This question aims to assess your resilience, adaptability, and coping mechanisms when faced with challenging situations.

How to Answer

When responding to this question, it’s important to showcase your ability to stay composed and focused under pressure. Highlight specific strategies you use to manage stress, such as effective time management and prioritization.

Example

“I’ve learned to manage pressure effectively through strategic planning and a proactive mindset. When faced with tight deadlines, I prioritize tasks based on their urgency and importance. Breaking down complex projects into smaller, achievable goals helps me maintain clarity and stay focused. Additionally, I believe in open communication with team members, creating a collaborative atmosphere where everyone can contribute ideas and share the workload. Overall, my approach involves a combination of organization, teamwork, and a positive attitude to successfully navigate high-pressure situations.”

2. What are your strengths and weaknesses?

Understanding your strengths and weaknesses is essential in assessing how well you align with the requirements of the software engineer role at Walmart. It provides insights into your self-awareness.

How to Answer

While answering, choose strengths that are relevant to the software engineering role and also give examples from your past experiences. Be honest but strategic in discussing weaknesses. Choose a weakness that is not a critical skill for the role. Discuss steps you’ve taken to address or mitigate this weakness.

Example

“One of my strengths is my strong problem-solving ability. I excel at breaking down complex challenges into manageable components. For instance, in my previous role, I successfully addressed an intricate coding issue by delving into the system architecture, identifying the root cause, and implementing an efficient solution. Regarding weaknesses, I can say that I used to struggle with delegation in the past, often feeling that it was quicker to handle tasks myself. However, I’ve actively worked on this weakness by realizing the importance of collaboration and team efficiency.”

3. Can you tell me about a time when you had conflicts with a coworker? How did you handle it?

Working collaboratively is important in a software engineering role at Walmart, and conflicts may arise from differing opinions. This question is asked to assess your interpersonal skills, your ability to resolve conflicts professionally, and how you maintain a positive team dynamic.

How to Answer

To answer this, select an example where the conflict was work-related and had a direct impact on the project. Emphasize how you approached the conflict. Highlight any steps you took to address the issue.

Example

“In a past project, a colleague and I had different opinions on a feature implementation. To address it, we had an open discussion, considered each other’s perspectives, and found a compromise that enhanced the overall solution. We documented our decisions, showcasing better collaboration. This experience emphasized the importance of effective communication and collaboration in resolving conflicts and finding mutually beneficial solutions.”

4. How do you stay up to date with the latest technologies?

In the fast-paced field of software engineering at Walmart, staying current with the latest technologies is crucial to delivering innovative solutions. This question aims to assess your commitment to continuous learning and adaptability.

How to Answer

To answer this question, mention specific websites, blogs, forums, or newsletters you regularly follow for tech news. Provide examples of how you’ve applied new technologies in your work or recent projects. Highlight your curiosity and enthusiasm for exploring new technologies.

Example

“I stay updated with the latest technologies by regularly following tech blogs like TechCrunch and engaging in forums such as Stack Overflow. I attend conferences to enhance my knowledge, actively participate in online communities, and collaborate on projects. I’ve also recently integrated the latest blockchain technology into a project, demonstrating my commitment to staying current and applying new knowledge in practical settings.”

5. Can you share an experience where you successfully optimized code for improved performance in a software project?

This question is asked at Walmart software engineer interview as it assesses your ability to enhance the efficiency of software, a vital skill for a company of Walmart’s scale and technological complexity.

How to Answer

To answer this question, briefly describe the specific situation where code optimization was required, emphasizing the challenge you faced. Describe the steps you took to identify areas for optimization and share outcomes.

Example

“In one of my previous roles, I encountered a situation where our e-commerce platform was facing sluggish performance during high-traffic events. To address this, I conducted a comprehensive analysis using profiling tools, identifying areas in the code that were causing delays. I implemented strategic optimizations, such as caching frequently accessed data and refining database queries. As a result, the platform’s response time significantly improved, leading to a 40% reduction in page load times. This optimization not only enhanced user experience but also ensured the platform could seamlessly handle increased traffic.”

6. How will you find the shortest path from a start node to an end node in a graph (2D array) using any shortest path algorithm?

Walmart relies heavily on software systems to optimize various operations, such as inventory management, supply chain, and customer service. This question tests your understanding of algorithms, data structures, and problem-solving skills.

How to Answer

Choose a suitable shortest path algorithm, such as Dijkstra’s algorithm or A* search, considering the characteristics of the problem. Write a clean and efficient code snippet that implements the chosen algorithm. Discuss any optimizations for scalability.

Example

“I would write a Python function using Dijkstra’s algorithm to find the shortest path in the given graph between two nodes. The code will include error handling for invalid inputs and be well-commented for clarity. I’ll ensure modularity and consider optimizations for scalability. Additionally, I’ll propose a set of test cases to validate correctness and efficiency, covering various scenarios.”

7. Given two strings, string1 and string2, write a function max_substring to return the maximal substring shared by both strings.

This question tests your ability to solve string manipulation problems, which are common in software development. Walmart relies on various software systems for inventory management; hence, efficient string manipulation is crucial for tasks such as searching for products.

How to Answer

Choose a suitable algorithm for finding common substrings. Write a function that implements the chosen algorithm. Ensure that the code is efficient and handles different input scenarios.

Example

“To find the maximal substring shared by two strings, I’d use the Longest Common Substring (LCS) algorithm. I’d initialize a 2D array to store substring lengths, iterating through the strings and updating the array based on matches. The maximum value in the array would give the length of the maximal substring. To optimize, I might explore reducing space complexity, perhaps using a rolling array. I’d propose test cases covering various scenarios to validate correctness and efficiency, ensuring the solution’s reliability in real-world applications.”

8. How will you implement logistic regression without an intercept term using basic gradient descent (Newton’s method), return regression parameters without penalties, and use numpy and pandas (no scikit-learn)?.

Walmart relies heavily on data-driven decision-making for various aspects. This question tests your ability to work with real-world data and build models tailored to specific requirements, which are essential skills for a Walmart software engineer.

How to Answer

Implement the logistic regression model in Python, using numpy and pandas. Apply basic gradient descent with Newton’s method. Write clean code and ensure the code handles edge cases.

Example

“I’d start by implementing the basic gradient descent with Newton’s method. Using numpy and pandas, I’d structure the code to optimize the log-likelihood as the loss function. In the code, I’d use clear variable names and include comments to explain each step. I’d also pay attention to handling edge cases to ensure the robustness of the implementation. For testing, I’d propose various scenarios, such as datasets with different characteristics and parameter configurations, to validate the correctness of the logistic regression model.”

9. Given a dictionary with keys of letters and values of a list of letters, write a function closest_key to find the key with the input value closest to the beginning of the list.

At Walmart, efficient data processing is crucial for tasks such as inventory management, order processing, and customer analytics. This question tests your ability to work with dictionaries and lists, perform basic data manipulations, and implement algorithms.

How to Answer

Choose a suitable algorithm for finding the closest value. Write a function, such as closest_key, that implements the chosen algorithm. Iterate through the dictionary. Return the key associated with the list containing the closest value.

Example

“I’d start by implementing a function called closest_key. I would iterate through the dictionary, comparing the input value with the elements of each list. The key associated with the list containing the closest value to the beginning would be returned. I would also use clear variable names and comments to enhance code readability. For example, I might use a loop to iterate through the dictionary, and for each list, I would compare the input value’s position with the list’s elements. I would track the closest distance and update the closest key accordingly.”

10. Given n dice, each with m faces, write a function combinational_dice_rolls to dump all possible combinations of dice rolls.

Understanding and manipulating combinations can be crucial for tasks such as inventory management at Walmart. This question tests your ability to generate and manipulate combinations, which is a fundamental skill in algorithmic problem-solving.

How to Answer

Choose a suitable algorithm for generating combinations. Write a function, such as combinational_dice_rolls, that implements the chosen algorithm. Use loops or recursion to generate all possible combinations of dice rolls.

Example

“I’d start by implementing a function called combinational_dice_rolls. I would likely use recursion to explore all possible combinations. The base case would be when the number of dice is zero, and I’d return an empty list. Otherwise, I would iterate through the faces on the current die, recursively calling the function for the remaining dice. I would also use clear variable names and comments to enhance code readability. For example, for each die, I would iterate through its faces and recursively call the function for the remaining dice. The combinations would be built up, and the final result would contain all possible combinations of dice rolls.”

11. You are given a transaction data frame containing transaction IDs, product IDs, and the total amount of each product sold, and a product dataframe containing product IDs and prices. Write a function to return a dataframe containing every transaction with a total value of over $100.

This question tests your ability to manipulate and analyze data using pandas dataframes, which is a crucial skill for software engineers in retail environments like Walmart for tasks such as sales analysis and optimization.

How to Answer

Write a function, named filter_transactions, using pandas to filter and manipulate dataframes. Utilize dataframe operations to calculate the total value of each transaction and filter transactions exceeding $100.

Example

“I’d write a function like filter_transactions. I would then use pandas to perform dataframe operations, first calculating the total value for each transaction by multiplying the amount sold by the product price. Then, I’d filter the transactions dataframe based on the total value condition and create a new column for the total value. For example, I might use pandas’ merge function to combine the transactions and products dataframes, calculate the total value, filter based on the condition, and create a new dataframe containing transactions with total values over $100.”

12. In a binary loan qualification model, how would you provide reasons for rejection to applicants, considering the unavailability of feature weights?

This question tests your ability to handle real-world applications of machine learning models and communicate results effectively. Understanding how to explain model decisions is a crucial skill for a software engineer role at Walmart.

How to Answer

While answering, propose explainability techniques that don’t rely on feature weights, such as SHAP values, LIME, or surrogate models. Discuss how you would implement the chosen explainability technique in the context of the binary classification model.

Example

“If tasked with providing rejection reasons to loan applicants without feature weights, I’d explore explainability techniques like SHAP values or surrogate models. For instance, using SHAP values, I’d quantify feature impacts on the rejection decision, offering insights without direct access to weights. Alternatively, a surrogate model could provide a simplified, interpretable representation for transparent communication with rejected applicants.”

13. Could you please tell me about the garbage collection process in Java?

This question tests your understanding of memory management in Java, a crucial aspect of developing robust and efficient software in a retail environment like Walmart.

How to Answer

To answer this, provide a brief explanation of garbage collection, highlighting its purpose in managing memory by identifying and reclaiming unused objects. Touch upon Java garbage collection strategies, including generational garbage collection.

Example

“In Java, the garbage collection process is handled by the Java Virtual Machine (JVM). There are various garbage collector implementations like serial, parallel, G1, and CMS collectors, each with its own strengths and use cases. The memory spaces, including Young, Old, and Perm/Metaspace, are used to categorize and manage objects based on their lifecycle. Java uses generational garbage collection, optimizing efficiency by promoting surviving objects. To optimize garbage collection in Java, developers often focus on minimizing object creation, using appropriate data structures.”

14. How will you implement LRU cache without using LinkedHashMap?

In a retail company like Walmart, where large-scale data processing is essential for inventory management and customer interactions, the ability of software engineers to implement an LRU cache efficiently is crucial for optimizing system performance and response times.

How to Answer

Clarify the requirement of implementing an LRU cache without using the LinkedHashMap class in Java. Choose a suitable algorithmic approach and data structures that can efficiently manage the LRU cache operations.

Example

“To implement an LRU cache without using the LinkedHashMap class, I’d use a combination of a doubly linked list and a hash map. The hash map stores node references in the doubly linked list, where each node represents a cache entry. On access or insertion, I’d move the corresponding node to the front for recent use, maintaining the order. Eviction involves removing the tail node, representing the least recently used item. The hash map ensures constant time complexity for direct access, optimizing retrieval. This approach balances insertion, retrieval, and eviction operations efficiently for managing the LRU cache.”

15. How would you reverse a string without changing the position of any special characters present in the string?

In a retail context like Walmart, efficient handling of strings is essential for tasks involving data processing, text parsing, and system interactions. Software engineers are expected to showcase their ability to manipulate strings effectively.

How to Answer

Choose an algorithmic approach that allows for the reversal of the string while maintaining the positions of special characters. Provide a concise explanation of the chosen approach, emphasizing how it addresses the constraints.

Example

“To reverse a string without changing the position of any special characters present in the string, I’d adopt a two-pointer approach. I would initialize two pointers at the beginning and end of the string and iterate towards the center. At each step, I’d check if both characters at the pointers are regular characters. If so, I’d swap them. If one or both are special characters, I’d adjust the pointers accordingly without swapping. This way, the reversal occurs only for regular characters, maintaining the positions of special characters.”

16. Given a binary array consisting of only 0s and 1s, create a Python function, equal_subarray, that returns the maximum length of a contiguous subarray with an equal number of 0 and 1.

This question assesses your ability to solve problems related to array manipulation and subarray analysis. Software engineers are expected to showcase their proficiency in algorithmic problem-solving and optimization at Walmart.

How to Answer

Choose an algorithmic approach that efficiently identifies and analyzes contiguous subarrays. Design a solution that involves manipulating the binary array to identify subarrays with an equal number of 0s and 1s.

Example

“ I’d approach this problem using a hashmap to keep track of the cumulative count of 0s and 1s. As I iterate through the binary array, I update the cumulative count and store the first occurrence of each count in the hashmap. The maximum length occurs when the same count is encountered again, indicating an equal number of 0s and 1s between those two positions. For example, given the binary array [0, 1, 1, 0, 1, 1, 1, 0], I would iterate through it, updating the cumulative count. At position 4, the cumulative count is 2, and I check the hashmap. Since I’ve encountered the same count before at position 1, the length of the subarray between positions 1 and 4 is equal, and it’s 4. I will continue iterating and updating the hashmap.”

17. Given three tables representing a forum of users and their comments, how can we detect if users are creating multiple accounts to upvote their own comments? Provide a query to display the percentage of users engaged in fraudulent behavior.

At Walmart, understanding and identifying suspicious user behavior, such as vote manipulation, is crucial for maintaining a fair and secure online platform. This question tests the software engineer’s ability to analyze data and design SQL queries to uncover potential fraudulent activities.

How to Answer

Propose metrics that could indicate fraudulent behavior, such as an unusually high percentage of upvotes on a user’s own comments. Create a SQL query that calculates the percentage of users engaging in potentially fraudulent activities based on the chosen metrics.

Example

“For identifying potential fraudulent behavior on the forum, I’d use metrics like the percentage of upvotes on a user’s own comments or patterns of repetitive voting. I’d design a SQL query to count upvotes, group them by user, and calculate the percentage of upvotes from the same user. This query would highlight users with suspicious voting patterns, aiding in the detection of multiple accounts created for upvoting. The query would consider user IDs, comment IDs, and upvote timestamps to analyze voting behavior effectively.”

18. Design a stack that supports push(), pop(), and retrieving the minimum value in constant time, using only the stack data structure.

This question tests your ability to design efficient data structures and implement fundamental operations. Being a software engineer at Walmart, these skills are important for creating data structures with specific functionalities.

How to Answer

Choose an algorithmic approach that allows for efficient implementation of the required operations. Design the stack structure, ensuring it meets the criteria of supporting push(), pop(), and constant-time retrieval of the minimum value.

Example

“To create a stack supporting push(), pop(), and constant-time retrieval of the minimum value, I’d use an auxiliary stack to track minimum values at each step. When pushing, I’d compare the new element with the current minimum and update the auxiliary stack. Pop operations would synchronize with the auxiliary stack. This approach ensures constant-time retrieval of the minimum value during sequences like (3, 2, 4, 1), maintaining efficiency using only the stack data structure.”

19. Given a table of user logs with platform information, count the number of daily active users on each platform for the year 2020.

At Walmart, data-driven insights are crucial for understanding user behavior and optimizing systems. Hence, software engineers need to demonstrate their proficiency in extracting relevant information from large datasets.

How to Answer

Write a SQL query that extracts and counts the daily active users for each platform from the user logs. Include conditions in the query to filter logs based on the year 2020 and group the results by date and platform.

Example

“To count daily active users on each platform from user logs for the year 2020, I would select log_date, platform, and use a COUNT(DISTINCT user_id) with a grouping by log_date and platform in a SQL query on the user_logs table. Filtering logs based on the condition that the year extracted from log_date is 2020 ensures a focus on that specific year, providing a concise way to analyze user engagement and obtain valuable insights for data-driven decision-making.”

20. Given a list of strings, write a Python program to check whether each string has all the same characters or not. What is the complexity of this program?

Software engineers are expected to showcase their ability to design a program that checks specific conditions within a given dataset. At Walmart, efficient and accurate handling of data, including strings, is essential for various tasks, such as processing customer information.

How to Answer

Choose a straightforward algorithmic approach to check whether all characters in a string are the same. Write a Python program that implements the chosen algorithmic approach, iterating through each string in the list and performing the necessary checks.

Example

“To create a Python program to check if each string in a given list has all the same characters, I’d use a simple approach. I’d iterate through each string, comparing each character to the first one. The program would return a list of boolean values indicating whether each string meets the condition. The code might look like:

def check_same_characters(strings):

return [all(char == string[0] for char in string) for string in strings]

The time complexity of this program is O(n * m), where n is the number of strings and m is the length of the longest string, due to the need to compare each character of each string in the worst-case.”

Here are some tips that can help you ace your Walmart Software Engineer Interview.

Understand the role and Walmart’s Culture

Firstly, get to know the specifics and requirements of the Software Engineer position at Walmart. After that, take the time to explore Walmart’s tech stack, gaining insights into the programming languages, frameworks, and tools commonly utilized in their software development.

Check out our Walmart Interview Guides to gain more knowledge about Walmart’s general interview process. You can also take a look at other data-centric roles that we cover, like Walmart’s Data Engineer, Analyst, Scientist, and Machine Learning positions.

Practice Coding Challenges

Begin by revising fundamental concepts such as arrays, linked lists, trees, and graphs. Make sure you have a strong understanding of algorithmic concepts like searching, sorting, and dynamic programming.

To sharpen your coding skills, you can practice our Interview Questions, where you can find all types of coding and data structure questions.

Update and Know your Resume

Update your resume and be prepared to discuss your resume in detail. Highlight key projects, achievements, and technical skills. Connect your experiences to the requirements of the software engineer role at Walmart.

Additionally, consider checking Interview Query’s Coaching services, where you can get personalized assistance in refining your resume from our expert coaches.

Prepare Behavioral Questions

Be ready to discuss your past experiences, projects, and problem-solving approaches with the recruiting team. Don’t forget to use the STAR (Situation, Task, Action, Result) method to structure your responses to behavioral questions.

Moreover, you can enhance your preparation by exploring Interview Query’s Interview Experiences feature, where you can gain valuable insights into the recent interview processes of individuals who have interviewed for similar roles.

Practice a lot and Be Yourself

Lastly, keep practicing and, most importantly, be yourself during the interview. Regular practice sharpens your technical and communication skills.

Consider Interview Query’s mock interviews to practice real interview scenarios. Engage with our Challenges feature to hone your problem-solving abilities further.

What is the average salary for a Software Engineer Role at Walmart?

The average base salary for a Software Engineer at Walmart Global Tech is $150,070 based on 631 data points. Adjusting the average for more recent salary data points, the average recent weighted base salary is $230,167.

Check out our full Software Engineer Salary Guide if you want to gain a better perspective on the salaries of SEs in various positions, companies, and more.

Which other companies can I apply to as a Software Engineer?

As a Software Engineer, you have a diverse range of opportunities with various companies in the tech industry. Depending on your career goals, interests, and desired work environment, you may consider applying to renowned tech giants like Google, Meta, Amazon, and Microsoft for challenging and impactful roles.

Read our Company Interview Guides, where you can find out more about different tech companies and their interview processes.

Are there any job postings for the Walmart Software Engineer role at Interview Query?

We aim to keep our job board updated with open positions at various tech companies, including Walmart. Please visit our Job Board to explore current openings and find relevant opportunities for the Walmart Software Engineer role and other positions in the tech industry.

The Walmart Software Engineer interview process can be nerve-wracking, but with the right preparation and following the resources at Interview Query, you can overcome the challenges and excel at every step.

By understanding the role, aligning yourself with Walmart’s culture, and honing your technical and behavioral skills, you can confidently approach each interview stage.

Additionally, if you feel like you’re missing out on any aspect of preparation, explore our Takehomes feature, where you can solve longer problems step-by-step using notebooks from different companies.

Best of luck on your journey to acing the Walmart Software Engineer interview!